Vision as se s sment and preparat ions for te s t ing chil dren ' s vis ion . A guide

for parent s , at t endant s and teachers

Eva Linds tedt

CONTENTS

I The development and prac t ical impor tance o f vis ion

I I Visual func t ions vis ion te s t ing

I I I Vis ion tasks and the child

IV Vis ion appraisal through behavioural ob servat ion

V Vis ion te s t s de sc ribed

Pho tographs $ Pe ter Hen r icsson

ELI SYN

Eva Linds t edt

Hogber gsg . 30

8— 1 1 6 20 STOCKHOLM

Sweden

I S$ N 9 1 -7836-005-6

The deve lopment and prac t ical importance o f vis ion

Seeing and i t s ut il isat ion are very much based on the proper ut ili sat ion of

visual impres s ions by the b rain . These impres s ions have to b e comb ined

with impre s s ions from o ther sense s , linked up with mo tor func t ions (move

ment s o f the head , body , eye and hand ) and proces s ed concep tually and

emo t ionally . A retarded child o f ten has an add it ional disab i lity which

affec t s the se proces se s , e . g . dis turbance s af fec t ing percep t ion , mo tor

skill s and emot ional development . This may be due to various degree s o f

developmental dis turbance or b rain damage and perhap s to the disrup t ions o f

the early mo ther-child relat ionship which inevitab ly oc cur if the child is

born premature ly , is in bad condit ion at b ir th or does no t re spond normally

to the mo ther ' s care and at tent ion .

One is o f ten at a lo s s to know the exac t degree o f a child ' s visual handi

cap . Perhaps i t is uncer tain whether the child can see at all . Somet ime s

one knows that the child can see but is uncertain o f hi s exac t visual

capac ity . This causes he s itancy when dealing with the child . How is one

to s t imulate vis ion when it is low or undeveloped $

If the child fails to make any progres s , one wonders what the reason can

b e . Is the‘

play material too dif f icult in visual t erms $ Does it make

exces s ive mental demands $ Is it the interpretat ion of visual impre s s ions ,

i . e . visual percep t ion , which is di s turbed in sp ite of normal visual

acuity $ Is vis ion b locked by mental s creening $

Other ques t ions also ar ise . How long are we to pers is t in our at temp t s at

$ ge t s tar te d $ $s t imulat ion , h ow long can we go on hoping that vis ion will

How vigorous ly are we to t rain the child $ This las t ques t ion is , not

leas t , p sycho logically impor tant bo th to the child and to his parent s .

The thing is to he lp the child achieve the b e s t po s s ib le to tal deve lopment .

Vis ion is an impor tant ins t rument in the child ' s deve lopment , but if hi s

vis ion is very low , undue emphas is on vis ion may do mo re harm than good .

Something has to b e known about the child ' s vi sual capacity if mis takes are

to b e avo ided .

I t is dif f icult to as se s s and t e s t the vis ion o f a smal l child in case s

where vis ion is low , and especially if the child is al so re tarded . In mos t

case s , however , vi s ion can be appraised , so long as the right procedure is

emp loyed . Examinat ion methods mus t be adap ted to the child ' s developmental

level and disab ility and the examinat ion mus t also have a c learly defined

purpo se . Ordinary vi s ion te s t ing me thods are mainly intended for adult s

and children who se development is relat ively normal in v arious respec t s,

and they'

have'

been. de f ined. for' par t icular' purpo ses , e . g . guidance for

t es t ing glas se s . Neither the circums tance s nor the purpo se o f vi sion

te s t ing are the same when we wish to inves t igate the vis ion of a small or

mul t ip ly handicapped child .

What i s the func t ion of vi s ion in the small child $

A newborn receives a ho s t of in mr e s sion s through it s various sense s . An

infant ha s an innate capac ity for receiving and , to some extent , proce s sing

the se impre s s ions . They support the child ' s capaci t y for achieving self

awarene s s , for ge t t ing it s bearing s , for experiencing the s tructure (ex

tent , po s it ion and shape ) o f space and things . They he lp the child as an

individual to use the world around i t , to b e ac t ive and in thi s way to

sat i s fy var ious needs , spo t intere s t ing obj ect s et c . Vis ion is normally

the mo s t impor tant source o f informat ion abou t the world already af ter the

f ir s t few weeks o f life .

Some vi sual capac ity is congenital . In order for vis ion to develop into a

serviceab le ins trument for the child ' s experience and daily act ivit ie s , ,

experience is needed in con j u c t ion with maturi ty .

How does vis ion operat e prac t ically $

The f ir s t task of vis ion is to provide spat ial orientat ion . When the child

grows £1 lit t le older , this orientat ion vi s ion furni shes guidance indoors

and outdoor s and is the foundat ion. o f ‘

W hat we term. locomo tor ‘vis ion .

Another e s sent ial task of vis ion is to supply de tailed informat ion about

various things $ de tails in the pat t erns of obj ect s $ and pic tures . This

de tail vis ion is , for example , the foundat ion o f reading vi s ion .

Orientat ion vision and de tai l vi s ion co—operate in the development proces s .

Orientat ion vis ion is conveyed primarily through the peripheral , outer par t

o f the re t ina , which o ccupie s the large space out s ide the macula . The

vision conveyed in the outer field of vis ion has quite a low . level of

awarenes s . One is no t altogether aware of the visual impre s s ions received

in this way . One does no t $ look $ at things in the outer f ield o f vi s ion .

This is no t t o say that they do no t produce reac t ions . One reac t s to thes e

visual impre s s ions all the t ime $ during guidance one automat ically avo ids

ob s tacle s without needing to think about doing so or becoming aware of

them .

If an obj ec t which is interes t ing or emo t ionally charged creps up in the

peripheral f ie ld , the visual impres s ion rapidly surface s in the awarenes s

and the direc t ion o f gaze alters by re flex . The image enters the macula

and can be examined . Visual impres s ions in the peripheral f ie ld o f vis ion

b r ov ~ xt to b ear .

thus serve the purpose o f s ignalling , so that the cons cious gaz e can b e

( 1 ) It is clear that , in pure ly prac t ical terms , vis ion play s a part in

the child ' s general deve lopment , i t s t imulate s and governs the child ' s

movement s and ac t ions . The child reaches for obj ec t s which he see s , crawls

or walks to reach them . The child ' s s e lec t ion o f obj ec t s will depend on

the emo t ional imp lica t ions o f what he see s . Even to a newborn , some ob

j ec t s are $ more fun $ than other s . Experience and maturity deve lop and

t rans form the emot ional charges o f thing s .

It is important to point out that the emot ional charging of visual impre s

s ions plays an impor tant part in s teering deve lopment . Visual percep t ion

mus t b e a po s it ive experience to the child .

(2 ) Vis ion is also a means of individual per sonal deve lopment . It serves

to make the child independent , ac t ive and self-re liant . Through his vis ion

the child perce ive s space and himself in relat ion to space and all the

things around it . He can f ind it s way about indoors and out doors , take

par t in mob ile game s , ride a b icyc le et c . He can ge t dre s sed , eat and

wash . In all the se things it is great ly as s is t ed by vis ion .

(3 ) The third prac t ical task of vis ion is that o f conveying visual informa

t ion in a more limited sense . Vis ion conveys knowledge about the child ' s

surroundings and i s fundamental £24 visual play o f all kinds , viz looking

at picture s , games , building , j igsaw puz z le s , looking at te levis ion and ,

no t leas t , learning the alphabe t and reading .

The prac t ical func t ion of vis ion is a useful point o f depar ture when ap

prais ing a child ' s vis ion . The fo llowing ques t ion can be asked and an

at tempt made to answer it $

Does vis ion play a real part in the child ' s general development $ Is the

child ' s vis ion suff icient to benef it his personal deve lopment and a c t iv i

t ie s $ Can vision be us ed for direct and spec ialis ed visual tasks $ To how

great an extent $

Visual func t ions vis ion te s t ing

The child us es hi s vis ion for prac t ical purpose s . The child ' s visual

behaviour expres ses his overall visual ab ility and re sult s from the inter

act ion o f several dif ferent visual func t ions $ visual acuity is a measure

of capacity for dis tingui shing de tails , contras t sens i t ivity is the pro

p erty which makes it po s s ib le to see the dif ference b e tween t he b rightne s s

of dif ferent surface s , the f ield o f vis ion conveys p ic ture s o f a large par t

o f one ' s surroundings , b inocular co-ordinat ion provides dep th o f vi s ion and

contribute s towards the gauging of dis tance s , darkne s s adap t ion enab le s us

to see in poor light , light adap t ion enab les us to ac cus tom our eyes to

s trong light and avoid b eing dazz led , colour vis ion enab le s us to dis t in

guish be tween dif ferent shades o f co lour .

The muscular movement s (oculo—mo tor func t ions ) governing the po s it ion of

the eye and the gaze deve lop s imultaneously and conj oint ly with the various

visual funct ions . As development proceeds , visual func t ions and oculo

motor funct ions are interdependent .

$ Focus ing $ one ' s gaze , keeping it

s t ill in order to examine something , fo llowing an obj e c t with one ' s eye s ,

$ s canning $ one ' s surroundings in search of intere s t ing vi sual informat ion ,

adj us t ing the re frac t ion power o f the eye to fo cus on obj ec t s at dif ferent

dis tance s (ac commodat ion ) all the se type s o f visual behaviour depend on

the outward and inward musc les o f the eye func t ioning and being at tuned to

one ano ther .

Space will no t allow me to go into further de tai l concerning all these

vi sual func t ions . Ins t ead I re fer to the book $ As se s sment of Vis ion in

Children $ ( see also page I mus t , however , t ouch on the comp lex condi

t ions which can prevail in children wi th low vis ion , for this very reason

of vis ion depending on so ma ny dif ferent func t ions and due to the possib

il i t y o f tho se func t ion s being damaged in various ways and to varying

ex t en t s .

Our commones t vis ion te s t s are intended for norma lly deve loped children and

presuppo se normal mo tor and concep tual deve lopment . They proceed direc t ly

in a t ion and f ie ld o f vis ion .

Comp le te ly dif ferent condit ions apply to children with impaired vis ion and

children who are re tarded or mult ip ly disab led . In these ch ildr en , ,i t is

common for vis ion dis turbance to affe ct many visual func t ions and also the

o culo-motor skills . Ordinary nmmh ods o f nwa su r emen t o f ten yield mis lead

ing re sult s or none at all . Other methods are needed ins tead . Bes ide s ,

vis ion te s t ing has to b e preceded by preparat ions and prac t ice . Real

succes s demands the part ic ipat ion of parent s , at tendant s and teachers .

Informat ion about a child ' s vis ion can be ob tained through

( 1 ) Obj ec t ive vis ion te s t s and ob servat ions o f the eye s .

(2 ) Subj ec t ive vis ion te s t s .

( 3 ) Behavioural ob servat ion .

Ob ject ive te s t s are tho se in which the child does no t part ic ipate ac t ively ,

e . g . t es t s o f the reac t ion of the pup il to light , elec tr ical response s from

the cereb ral cortex when vis ion is s imulated , and so on . These t e s t s

invo lve triggering and recording re flexe s and elec trical phenomena .

Sub jec t ive vis ion te s t s require ac t ive and care fully spec ified part ic ipa

t ion by the child . The re sult will depend to a great extent on the child ' s

ab ility to under stand ins t ruc t ions and per form. the task. The child ' s

mental and mo tor capacity is crucial , for example , when the child is asked

to name or point to f igure s , compare and match p icture s , push a but ton when

he see s an obj ec t , and so forth .

Be low , on page 26 , I will b rie f ly summarise the commones t obj e ct ive and .

subj e ct ive vis ion te s t s .

Behavioural ob servat ion is le s s widely used as a bas i s o f vis ion appraisal .

We tend to prefer informat ion which is exac t and quant if iab le . And indeed

it is important for te s t ing methods to be dependab le and to yield re sult s

which can be compared from one occasion to ano ther and from one child to

ano ther .

Turning to the pract ical purpo se o f vis ion te s t ing , we f ind that perhap s it

is no t always so very impor tant to be ab le to quantify the child ' s visual

acuity . Ins tead we once again ask ourse lves

What is the level o f the child ' s vis ion in terms o f pract ical usefulnes s $

Behavioural ob servat ion is a very good way of answering thi s ques t ion . It

is quit e po s sib le in ) devise rout ines whereby behavioural ob servat ion can

provide a measurement o f the level o f vis ion which can be recorded and used

for purpo ses of comparison next t ime we appraise the child ' s vis ion in the

same way .

There are no hard and fas t boundarie s be tween behavioural ob servat ion and

subj e ct ive vis ion tes t s . If the visual environment is modif ied in such a

way that behaviour is governed by s tandardised and graded visual obj e ct s ,

one approaches the principle o f subj e ct ive te s t ing . The more the child has

to take part ac t ively and in a part icular way , the more clo sely the s i tua

t ion will re semb le that o f a subj e c t ive vi s ion tes t .

In b ehavioural ob servat ion we are concerned with the child ' s aggregate

visual capacity . I t is hard to deduce from this the measure o f an in div i

dual vi sual funct ion . S ince a prac t ical vi sual task of t en makes spec ial

demands on a cer tain visual func t ion , one can s t ill ob tain measurement s o f

individual visual func t ions by means o f behavioural ob servat ion . If the

s ituat ion is s implified and behavioural ob servat ion is comb ined with regis

t r a t ion , this can provide a foundat ion for very reliab le data . Thus pre

f e r en t ia l looking is emp loyed for exact det erminat ion o f visual acuity and

contras t vi s ion in infant s ( s ee the book $ As se s sment o f Vis ion in Child

Contras t vi s ion and f ie ld o f vis ion are par t icularly impor tant for spat ial

orientat ion and guidance .

The child ' s ab ility to cope with de tailed vi sual tasks will depend mo s t ly

on visual acuity .

Percep t ion of shape s which are no t unduly small , i . e . the mo s t everyday

art ic les in the child ' s surrounding s , doe s no t demand good acuity but doe s

require reasonab ly good cont ras t vi s ion .

Vis ion level visual sphere

When thinking in prac t ical t erms , it is natural t o speak o f level o f vis ion

and visual sphere . I have cho sen to grade visual capacity into four levels

o f vis ion . These are shown on p . 45 t ogether with examp le s o f the vi sual

tasks which a child can cope with at each leve l . , I n the char t I have also

t ried t o indicate the visual acuity roughly corre sponding to a cer tain

level o f vis ion . These re lat ions are only approximate , s ince a great deal

depends on the s tate o f o ther visual func t ions and also on the child ' s

general development . The chart is only intended as an aid , no t as an exac t

s cale . (p . 45 )

By visual sphere I mean how far away the child can see , or rather how far

away an obj ec t can b e and s t ill arouse the child ' s visual react ion . The

visual sphere depends bo th on visual capaci ty and intere s t . Normally the

infant has a limited visual sphere $ at f irs t it can only see a few deci

met res , and soon af terwards half a metre away , and at the age o f 1 year it

can see things quite a cons iderab le di s tance away . Between the ages o f 2

and 4 and even further up the age s cale , one can ob serve a rapid decline in

t he child ' s visual intere s t when an obj e c t i s moved 4-5 metres away . Even

ordinary ‘vis ion te s t ing dis tance s (5-6 metres ) can. make a dif ference ,

causing the child to part icipate badly through lack of interes t , and thus

yielding mis leading te s t re sult s . Feelings are very impor tant here . The

child can see his mother a long way away and runs to mee t her , but he doe s

no t re spond at all when a p ic ture is disp layed a few me tres away in a te s t

s ituat ion .

The visual sphere o f mentally re tarded children is of ten reduced due to

their inab ility to mob ilise intere s t , unles s there is an emo tional contac t .

Emot ional contac t usually only occurs if the person or thing is close to

the child . Vis ion impairment also reduces the visual sphere , because the$

child canno t clearly see obj ect s a long way away .

Vis ion tasks and the child

Communicat ion

Vis ion is a means o f communicat ion be tween the child and o t he r . peop l e / t h e

surrounding world . Other sense s are al so used for communicat ion . A child

with impaired vi s ion has to use the sense or $ channel o f communicat ion

which works b es t . Conversely , parent s and at tendant s have to f ind and us e

this $ bes t $ channel as well . This is e spec ially impor tant to s tar t with ,

when making contac t with the child . Once contac t has been e s tab lished

through one sense , e f fort s can b e made to arouse the child to contac t

through o ther sense s a s well .

Vision , even if it is low and fragmentary , is extreme ly important no t only

for communicat ion but also as a par tner for the o ther senses in the develop

ment proce s s . Parent s and at tendant s of ten realise thi s very well and try ,

qui te right ly , to e licit a visual re spons e f rom the child as soon as po s s

ib le .

S creening o f f

The aim i s to es tab li sh contac t with the child and to s t imulate it s deve lop

ment as far as pos s ib le . To a great extent this is done by providing the

child with enj oyab le experience s . Thi s has a great deal to do with suc

ces s . Exercis es o f various kinds , daily ac t ivity and game s are all tasks

to b e performed . Suc ce s s in enj oyab le and provide s an incent ive for more

ac tivity . Failure is no fun $ the child lo ses intere s t and b ecomes pas s ive .

This is a great dif f iculty for all parent s and educator s . They want to

s t imulate the child , fun$ the child rej ec t s various sugges tive ac t ivit ie s

and game s . It s creens i t s e lf o f f in pas s ivenes s and se lf-ab sorp t ion . This

may be part ly due to the chi ld ' s act ivity never having go t s tar ted , b ecause

i t s sensory percep t ions have been too weak or becau se too di f f icult a task

has b een se t . In the case o f vi s ion , this means that the visual obj ec t has

not b een capab le o f s t imulat ing a poorly func t ioning visual sys tem . In

some case s , mo s t o f ten where there is addit ional handicap invo lved b ecaus e

o f extens ive b rain damage , s creening of f leads to the serious condit ion of

aut ism .

Encouragement and failure in vis ion

Visual experience in it self is a reward to the child who can be urged into

ac t ivity , which in turn deve lops vis ion . A benign circ le is s tarted . The

reac t ions o f o ther peop le , parent s and the at tendant are also impor tant .

When a child has low vis ion , the natural thing is to reward him when he can

see , when he cope s with a visual task . Seeing comes to mean be ing clever

and making mother and father happy . Conversely , o f course , no t seeing is a

failure which means that the child has no t been clever and that mother and

father are upse t . The child feels inferior and doe s no t develop self-con

f iden ce . When this happens it may choo se no t to see . This is one way for

the child to avo id failure and pro te c t it s se lf—e s teem . The child s creens

it self o f f f rom visual impre s s ions . This is an unfortunate turn of event s ,

and a vicious c irc le ensue s , because the low vi s ion is no longer s t imulate d

at all , it s top s short or becomes re trograde . The child can also pret end

to see unt il , one day , the pretence b reaks down and he i s $ caught $ . Thi s

i s also a severe b low to the child ' s ego ident ity and se lf—e s teem .

So what are parent s to do $ Here as in all pedagogics , the secre t is to

act ivate for succe s s . One mus t try to make $ the fun $ part o f the ac tual

game , the ac t ivity , as Oppo sed to the reac t ions o f other peop le (e . g .

p raise ) . This means keep ing game s and‘

everyday tasks above the child ' s

vis ion leve l . When slight ly more dif f icult tasks are de s ired , the child

should no t no t ice very c learly if he is unsucce s s ful . Of course , the child,

will frequent ly no t ice all the same that he doe s no t see we ll , but feelings

connec ted with failure can be toned down . By giving the child tasks of

which i t is visually capab le , one can avoid a day full o f disappo intment s .

(The BUST tes t , de scrib ed b e low on page 34 , has been de s igned to work with

out too many If one is p laying a game with the BUST cards with

perhap s a wheel and clock , the child may perhap s fail to dis tinguish be

tween the two p ic ture s at a certain s iz e , put t ing a clock together with the

wheel s or vice versa . This can be tacit ly accep ted , there will be no

disappo intment s and the game can go on . And yet one has s t ill found out

s omething about the child ' s vis ion level . Simi larly , the LH te s t is de

s igned so that , when the pic tures become indis t inc t , all the f igures will

look like circle s to the child , and the child will therefore fee l that it

can at leas t see . )

Somewhat dif ferent c ircums tances app ly , o f course , if the child is b lind .

The child does no t experience failure in the ac tual mat ter o f s ee ing . The

ro le o f the b lind child is more s traight forward bo th to the child himse lf

and to tho se around him . No impos s ib le vi sual demands are made . The child

may of course be powerfully af fec t ed by his parent s dispair , but this is a

dif ferent psychological prob lem .

Visual hab ilitat ion

By hab ilitat ion we mean making skilful We want our children to be come

skilful in handling their world , be it a small one or a large one , and

whether they themse lves have small or large re source s . The child mus t

b ecome skilful at his own level and on his own condi t ions . He does so by

act ively us ing his re source s . He mus t b e s t imulated and deve loped , he mus t

gain experience and mature .

If thi s is achieved , development ge t s go ing under it s own s team within

the limit s o f the individual child ' s po tent ialit ie s . I f this is no t a ch iev

ed , even the be s t exercis e and s t imulat ion programme s will yield a poor

re turn .

The p erson lead ing the child ' s deve lopment needs t o know about the child ' s

visual circums tance s in order to provide the b e s t po s s ib le help .

One mus t b e ab le to appraise a vi sually handicapped child ' s vis ion , no t

exac t ly , but so as to ident ify the child ' s vis ion leve l ( c f . page

This makes it po s s ib le t o adap t the visual environment properly , t o supp ly

the child with s t imulat ing p lay materials and to p lan and conduc t visual

hab ilitat ion correc t ly .

The child ' s vis ion mus t be s t imulated at the child ' s current leve l . This

provide s the be s t chance o f arous ing the child ' s intere s t and trigger ing

development . During thi s pro ces s , the child ' s vis ion needs t o be r e

appraised and new vision data have to b e incorporated in everyday a c t iv i

t ie s , game s and exercis es .

In this way , vision appraisal visual hab ilitat ion are intertwined .

Preparat ion for more exact te s t ing o f individual visual func t ions

t a in ed$ into the b argain $

.

Vis ion appraisal through behavioural ob servat ion

The behaviour o f a seeing child is based on visual impre s s ions . This is

the key to behavioural ob servat ion as a bas is for apprais ing visual capa

c ity .

The child is act ivated by vi sual impres s ions and reac t s

The child ' s intere s t is aroused , the child becomes at t ent ive .

The child ' s oculo-mo tor skills are ac t ivated , the child cont ro ls

gaze so as t o focus on and fo llow the visual obj ec t .

The child fo cuses on obj e ct s and undertakes direc t ive reaching to

hold o f something .

The child fo cuses on obj ec t s and crawls o r walks towards them .

The child reac t s emo t ionally t o $vi sual impre s s ions , smile s at

mother ' s face , at the do ll , at the feeder bo t t le , at his food , at

c lo the s , and is up se t when mother looks cro s s or the b o t t le is

moved .

Vis ion as se s sment is based on these s imple fac t s . I t goes wi thout saying

that the child only reac t s to and is only act ivat ed by visual impres s ions

which it see s . The extent to which a child see s obj e c t s will depend on

their shape , d is t inc tne s s , contras t to the ir surroundings , s ize and , also ,

the ir dis tance away from the child .

Vis ion as se s sment is founded mainly on ob servat ions of the child ' s spontan

eou s b ehaviour , but also on ob servat ions o f the child in a modif ied environ

ment , when confronted with tasks which the ob server has introduced and to

some extent contro ls . One ob serve s , t es t s , pract ise s , and tes t s again .

The child ' s surroundings , p lay 'mater ials and tasks are adap ted to it s

vis ion level , and af ter a t ime a new vision as se s sment is under taken , new

measures o f s t imulat ion are introduced , and so on .

Based on s imple ob s ervat ions o f the chi ld ' s spontaneous behaviour in every

$ exercise— t e s t-exerc ise $ are int roduced into hisday life , element s o f

everyday rout ine . This can be done at mealt ime s , during game s , indoors and

outdoors , during ins truct ion and at s chool . Parent s , at t endant s and teach

ers have very great opportunit ie s o f ca t ch ing‘

t he child ' s at tent ion , s t eer

ing his interes t and above all ut ilis ing his b right $ moment s , i . e . moment s

when the child is balanced and ready for tasks o f dif ferent kinds .

In order to b e ab le to as se s s the child ' s vis ion by ob serving his behav

iou r , one mus t be ab le to interpre t behaviour in visual terms . One needs

to know what vis ion is needed in order to cope with one or other visual

task . Some of these relat ionship s are illus trated in char t 1 (page

It is also impor tant to know about the normal development of visual be

haviour , e spec ially during the f irs t year o f life , at a low level o f matur

ity . Retarded children somet imes disp lay behaviour belonging to 51 lower

mental age than that corresponding to their b io logical age .

An infant reac t s to light and contras t s between light and dark firs t o f

all . In these reac t ions , behaviour is almo s t ent irely condit ioned. by

ref lex and is congenital . Mental experience s soon begin to play a part $

emo tion , curios i ty , lus t for ac t ivity govern‘

behaviour in relat ion to

various vi sual s t imuli .

Here i s a li s t o f everyday behaviour which can easily be observed and which

one should try to no t ice in the child .

The child turns his head towards a window (newborn ) .

The child fo cuse s on various visual obj ec t s and fo llows them with his gaz e .

/

A torch , somebody ' s face , the bo t t le ( later on ) , toys .

Vi sual contac t is es tab lished with the child . This means that one can

ob serve changes in the child ' s facial expre s sion indicat ing that the child

can see one ' s eye s . (4-7 weeks )

The child react s to hi s own ref lec t ion . He soon also takes an interes t in

other children .

The child plays with his hands . (3 months )

The child reaches for things .

The child crawls towards things and avoids ob s tac le s in hi s path .

The child s tops while crawling to inves t igate , visually , small obj ec t s in

his path $ he picks up crumb s and dus t , threads e t c . (8-9 months )

Towards the end o f the f irs t year , visual contac t can be used to play

$ peek-a-boo $ , which all children enj oy .

The child examine s things visually by lif t ing them to his eye s .

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Te s t ing and exercise methods for impaired vis ion

If impaired vis ion exis t s (n $ i s suspec ted , the visual environment can be

modified in various way s and the child ' s behaviour kep t under ob servat ion .

I ll . 1 . Drawing of a

face which can be used

to te s t the child ' s

ab ility to focus .

(Af ter Lea Hyvarinen . )

Ill . 2 . Eas ily— seen bo t t le ho lders . (Af ter Lea Hyvarinen .

( 1 ) Lack o f visual contac t . $ o c lo s er , put t ing your face 1 0- 20 cm in

f ront o f the child . Make sure that your face is lit up , so as to make it

d is t inc t . Make-u p can be an advant age , b ecause it b r ings out the eyes and

mou th . On e can also use a p icture o f a face , with the eyes and mouth

sharp ly drawn . Always make sure that the child is no t daz z led and that

there are no di s trac t ing visual obj e c t s behind you (a lamp or a window) .

The child ' s vi sual contac t may develop late , and so one should cont inue

working with the child , with one ' s face at c lose quar ters , frequent ly and

for several months . Visual contac t can also b e used in order to as se s s the

child ' s vi sual sphere . Approach the child from a di s tance and no te the

di s tance at which it makes visual contac t . Peek-a-boo is a variant o f

visual contact which all children ge t a lo t o f fun out o f . In this way ,

perhap s , one can cap ture the child ' s intere s t even if visual contac t i s

s luggish . Peek-a —boo is also a good way of apprais ing the child ' s di s tant

vision and visual sphere . The same goe s for imitat ive games .

Th e child ' s own re fle c t ion can be used to arouse visual intere s t and to

s t imulate and deve lop the child ' s ab ility to perceive a face and imitate

movement s . A mirror can be put up clo se to where the child plays and the

child po s it ioned so that he can eas ily see himself in the mirror .

Ill . 3 . Sugge s ted play

area arrangement . All

o f a sudden a child

cat che s s ight o f him

self in the mirror .

Remember that the light ing mus t be good (i . e . supply adequate light without

dazz ling ) and that the re flect ion in the mirror will be twice as far away

as the mirror it se lf . The mirror , therefore , should be p laced clo se to the

child .

( 2 ) Def ic ient ab ility to fo cus on obj ect s

A torch at clo s e quarters is a good s tart . It is also a good idea to use a

c learly drawn picture of a face ( see ill . 1 ) or a do ll with dark eyes and

mouth and a b right face , e . g . a rag-do ll . Ho ld it clo se and in good light

ing to dis cover whe ther the child focuse s at all . A face i s the mo s t

intere s t ing thing fo r an infant or toddler t o look at . S tark contras t

af fords the be s t s t imulus . Other di s t inct pat terns are also good , e . g . LH

play material and b ot t le ho lder s , ball s , cube s , beads .

I ll . 5 . Thi s is one way of te lling in s tant ly how the child fo cuses on the

light,seeing how she direc t s her hand towards the torch and also checking

that the pupils contrac t when the light enters them .

No tice what s iz e o f obj e c t the child can see and fo llow with hi s gaze . Try

to work out the crit ical dis tance . Once you have an idea o f the vis ion

level which the child is capab le o f , you can make sure that the child has

suitab le visual obj e ct s clo ser at hand , i . e . you $ divers ify $ the visual

environment and achieve an adapt ed s t imulus . Lilli Nielsen ' s s t imulat ion

mat erial includes quite a lo t o f material o f this kind . For children with

poor vis ion , one should make sure that the visual environment i s no t t oo

muddled or c lut t ered . Dis t inct ly shaped toys in dark or b right co lours

(b lack , white , red , yellow) are part icularly useful at low vis ion levels .

Emv ir onmen t a l modif icat ion in terms o f light ing and co louring is j us t as

impor tant as suitab le toys . Shiny tab les and f loor s produce dis t rac t ing

re flect ions , and so too can shiny toy s .

(3 ) Def ic iencie s in the deve lopment o f eye-hand co-ordinat ion

The child doe s no t play normally with hi s hands . J o in the child ' s hands

together in front of hi s eye s , pre ferab ly in good light ing agains t a dark

b ackground . Try in this way to draw the child ' s at tent ion to hi s hands .

Repeat this manoeuvre frequent ly .

The child doe s no t reach for things . Place the child on hi s s tomach over

your knee or on a s too l and put visually suitab le obj ec t s within reach .

Use can b e made o f LH p lay material for infant s , balls , a mus ical b ox ,

do lls et c . Help the child to grasp things and to move them towards hi s

eye s for examinat ion .

I ll . 5 . This po s it ion makes it eas ier for the child t o move hi s arms and

hands forward , and obj ec t s can be more eas ily placed within vis ib le range .

(Af ter Lillie Nielsen . )

(4) Reduced visual acuity $ one no t ices that the child can see b ig things

but no t small one s .

One should s tar t by apprai s ing the level of vis ion . The child can lie on

the f loor or s it at a tab le . Put out dif ferent ly siz ed toys for the child

to reach for and take ho ld o f . One can also use rai s ins , f lakes , smart ie s

and hundreds-and- thousands . One can vary the underlay (a pale underlay fo r

rais ins i s easy , a dark one is dif f icult ) .

If the child is suf f icient ly mature , vi sion as se s sment can very we ll b e

combined with $ playing shop s $

I ll . 6 . Obj ec t s for tes t ing near vi s ion $ rais ins , smar t ie s , beads , nib

sugar and hundreds-and-thousand s . Dif ferent backgrounds serve to vary the

visual task .

If the child has diff iculty in seeing the obj ect s , t ry al tering the light

.igg . When s iz e is ge t t ing crit ical , the child will very o f ten show it by

crouching or leaning forward. Or again the child may lo se intere s t o r

s tar t fumb ling with it s hands and us ing it s sense o f touch ins t ead o f it s

eye s . In this case the dis tance can be reduced by b ringing things clo ser

and no t ic ing whether t h e child i s then ab le to see them . It is a good idea

to o ff er a child a magnifying glas s .

I ll . 7 . A magnifying glas s can be fun to t ry .

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(5 ) Def icient orientat ion vi s ion $ The child bumps into ob s tac les , baulks

at mob ile games , misj udges kerb s . In cases of thi s kind it is important to

no te whether weak lighting aggravate s the prob lems . Either way , orienta

t ion Oppor tuni t ie s indoor s can be improved by means o f be t ter lighting .

$ ood lighting and colouring , producing cont ras t ive ef fe c t s , fac ilitate

spat ial percept ion and serve to de lineate surfaces . Thi s he lp s children

having special prob lems with their orientat ion vision and it al so help s any

o ther children with poor vi sion . So environmental modificat ion o f this

kind is always advisab le .

Some t imes , however , s t rong lighting may cau se the child mo s t dif f iculty .

One s imp le. expedient$ is t o ieliminate daz z ling light source s , e . g . f it

b linds to windows , and then see if the child cope s be t t er .

( 6) Deviat ing oculo-mo tor b ehaviour . The commones t deviat ion is s $uint

ing . Many normally sighted children squint , and this af fe ct s their b ino

cu l a r co-operat ion and also the visual deve lopment of the squint ing eye .

Vi s ion impaired children o f ten squint , but they can al so have deviat ions in

the movement pat tern o f one eye . It is important for the vi sual funct ion

that the child should b e ab le to fo cus , trace and perform scanning move

ment s . Irregular , ro lling movement s o f the eye s comb in ed i t h insuffic ient

ab ility to fo cus indicate yg£y_

l ow vis ion . Firs t and foremos t in this case

one mus t t ry to develop the ab ility to focus ( see 2 , above ) and visual

contac t . Nys tagmus is also a common phenomenon which sugges t s impaired

vis ion , but vis ion in cases o f this kind can vary a great deal . It i s

use ful to no te whether the child ' s nys tagmus varie s ac cording to the dir e c

t ion in which he is looking . One o f t en see s the child twis ting and turning

his head , peering , and looking through one corner o f his eye . Thi s is a

s ign that the child has vi sion and is exert ing himself to improve vi sual

condit ions by p lacing hi s eye in the direc t ion where it will be mo s t s ta

t ion a r y . In the case o f a child who focuses badly , the onset o f this type

of b ehaviour sugges t s that visual deve lopment ha s go t under way . In o ther

words , it is a good s ign and mus t no t b e counterac ted . The feas ib ility o f

us ing aids , however , can. b e prej udiced'

by thi s type o f‘

head. po s ture .

Measure s then may there fore have to be cons idered for altering the dir ec

t ion of gaze by surgery ( to the muscle s of the eye ) or by means o f spec ial

glas se s . Failing accommodat ion is dif f icult to spo t . Poorly s ighted

children look clo se $ , whether they can accommodate or 'not . Mus cular

di sorder s in the eye should always b e inve s t igated by an eye spec ialis t .

I ll . 1 2 . What is the picture on the card $ The girl t rie s to b ring the

pic ture into her f ield o f vis ion , searching and peering at dif ferent

angle s .

Vision te s t s des cribed

Ob jec t ive te s t s

Obj ect ive te s t s are mos t ly the doct or ' s bus ine s s . They involve ob serving

the outward appearance and inward s tate of the eye s , their po s it ion and

spontaneous movement s and certain ref lexe s . They can also involve regis tra

tion of e lec t rical re sponse s to visual s t imulus .

There is a lis t o f the commones t obj ec t ive te s t s o f visual func t ion .

( 2 )

( 3 )

(4)

(5 )

( 6 )

(8 )

Appearance o f the eye s . Ophthalmoscopy .

Po s it ion and spontaneous movement s o f the eyes $ ro lling nys tagmus ,

s quint ing , peering . Direct ion of gaze , compuls ive head pos ture .

Pupil reflexes $ pupil cont rac t s when light enters the eye .

Blinking re f lexe s $ the chi ld b links when a hand suddenly appro ache s

it s eye . For the sake o f dependab ility , this tes t should be performed

with a pane o f glas s between the hand and the child .

OKN , Op tokine t ic ny s tagmus . J erky movement s o f the eye , ny s tagmus ,

can be produced by ro tat ing a b lack-and—white s triped drum in f ront o f

the eye , in various direct ions and at various speed s .

ER$ , elec trore t inogram , i . e . examinat ion of elec trical charges in the

re t ina .

VEP , visual evoked po tent ial $ e lect rical re sponse s from the visual

cortex of the b rain are regis t ered when the eyes are s t imulat ed with

various light obj ec t s .

Sc ias copy , i . e . measuring the re fract ive rat io s o f the eye (not a

vis ion te s t , but an impor tant preparat ion for one , since it shows what

lenses the child may need for the vis ion t es t ) .

Obj e c t ive te s t s supp ly informat ion on cer tain bas ic prerequis i tes of

vi s ion , whe ther the eye can shape p ic ture s , whe ther the vi sual sys tem can

t ransmit visual impre s s ions , whether cer tain re flexes are in working order .

VEP also supp lie s some informat ion about the s tat e of the visual cortex ,

but no t really about ac tual percep t ion of the visual image .

For further par t icular s , re ference is made to $ Asse s sment o f Vi s ion in

Children $ and $ Ear ly Visual Deve lopment $ (p . 46 , no te s 1 , 5 )

Sub jec t ive vis ion te s t s

Subj e ct ive vi s ion te s t s are inseparab le from behavioural ob s ervat ion .

Several subj e ct ive vis ion tes t s invo lve ob serving the child ' s b ehaviour .

Somet imes the case can be used in bo th ways $ one can make do with ob serving

a chi ld ' s spontaneous reac t ion to te s t mater ial , or e lse one can give the

child ins t ruc t ions and ask for part icular answers . In some case s the te s t

material can b e used t o prepare the child fo r vis ion te s t s .

Vi s ion te s t s are usually performed by pro fe s s ional p ersonnel , viz a $ P , a

nur se at the child care centre , an oph t h op t r is t , an as s i s tant oph t h a lmo l o

gis t , a remedial t eacher o r a team . At all event s , the per sons re spons ib le

for preparing the child mus t be to ld a cer tain amount about the te s t s , the

pro cedure emp loyed and what the te s t s are de s igned to measure . There are

two rea sons for preparing the child . One o f them is to give the child

general pract ice in tackling the visual tasks , and the o ther is t o fami liar

ise the child with the concre t e obj ec t s , p ic ture shape s and procedure s

o ccurring in various te s t s . The child wi ll then be ab le to recognise the

material and will under s tand what the te s t s ituat ion i s all about .

The be s t vi s ion te s t re sult s are ob tained in the child ' s accus tomed surround

ings . But it i s s eldom pos s ib le for vi s ion tes t s to be perfo rmed in the

home or at s choo l . This ma ke s i t all the more impor tant fo r the child to

b e prepared so that , when the vi s ion te s t takes p lace at the child care

cen t r e /medica l r ecep t ion /pa edia t r ic ophthalmo logical c linic or Ihn v vis ion

clinic , the child will at leas t no t be complet ely unfamiliar wi th the

things used and the s ituat ions invo lved .

An obj e ct ive examinat ion of the eye s and visual capacity should always

precede the subj ect ive vis ion te s t s and ought pre ferab ly to oc cur on a

separate , previous oc cas ion . It will then be known whether the child needs

glas se s and vis ion te s t ing can proceed with proper correc t ion . At tent ion

can then be concent rat ed on vision te s t ing and there will be no need fo r

any simultaneous examinat ion of the eye s af ter adminis trat ion of eye—drop s .

Mo s t vis ion tes t s are mainly concerned with measuring visual acuity and

some t imes the fie ld o f vis ion , and they are le s s frequent ly concerned with

o ther ‘

V i sual. func t ions ( contras t. vis ion , colour ‘

V is ion ) . Binocular'

co

ordinat ion te s t s are also common , but I shall no t be re ferring to them in

thi s guide .

As s ta ted earlier , subj ec t ive vis ion te st s require the part ic ipation -o f

7

mental func t ions $ at t ent ion , interes t , intelle c tual operat ions an d , f r e

quent ly , speech and mo tor skills .

Demand s in the se respec t s vary

( l ) Merely ident ifying obj ect s or p icture s and in some way conveying what

i s seen (ge s ture s , speech , po int ing , fe t ching

(2 ) Ident ifying and comparing concre te obj ec t s or pic tures . Unders tanding

same-dif ferent , matching , and at the same t ime po inting to , naming o r

piling up things which are s imilar .

The tes t obj e ct s ( things , p ictures ) included in the t es t s may be 3—dimen

s iou al ,concre t e obj ect s or 2-dimensional p icture s depic ting concret e

obj e ct s,or ab s t rac t symbols (e . g . a circ le , s quare or t riangle ) .

The pic ture shape s may be s imp le , symme trical , or they may include more

dif f icult element s , e . g . element s requiring the child to dis t inguish be

tween u p and down , le f t and right (determinat ion o f direc t ion ) , which is a

superior mental func t ion .

The te s t s may present iso lated symbo ls , several symbols in a row ( the

dis tance between symbols equalling the width of the symbo ls themselves ) or

in close groups ( corresponding to the let ters o f a word ) .

Vis ion te st ing also takes p lace at various d is tance s . Long di s tanc e usu

ally means 3-6 metre s , c lo se $uar ters mos t ly means 25-50 cm . As we have

already s een , the child ' s visual sphere is reduced by low vis ion and , in

cer tain case s , by re tardat ion . There is no thing to prevent vis ion te s t s

b eing perfo rmed at a short er dis tance than is commonly the prac t ice and the

re sult s converted . This is quit e easy , because vi sual acuity i s inversely

propor t ional to dis tance (e . g . the value ob tained at half the te s t ing

dis tance is twice as high and there fore has to be halved in order to be

correc t , see ref . 2 , page On the contrary , i t is an advantage and

very advi sab le always t o b egin with shorter t e s t ing d is tance s in cases

where low vis ion or a reduced visual sphere is suspec ted . I t is als o

p sychologically pre ferab le to s tart c lo se to the child , so that he will

fee l clo se contac t with the person conduc t ing the t es t . One doe s no t then

move further away until , eventually , the child has been encouraged by

succes s . Accordingly , it is be s t to b egin vis ion te s t ing at clo s e quarters

and to save more long—range t e s t ing until later . S tar t with a te s t at

c lo s e quarter s ( 1 0-1 5 cm) and , if this turns out well , change to the

di s tance for which the te s t is de s igned (e . g . 25 cm) . In long-range te s t s ,

s tart at -1 metre , gradually increas ing the di s tance i f the child

answers conf ident ly . Measurement at a dis tance o f 3 me tres is frequent ly

suf f icient .

Light ing i s impo rtant in all vis ion te s t ing . It is equally impor tant when

making preparat ions for t e s t s . Valuab le informat ion can also be ob tained

by te s t ing vi s ion in dif ferent light ing condit ions , but thi s i s s eldom

ac tually done . When making preparat ions for vis ion te s t ing , one can ob

s erve whether the re sult s vary a great deal with the light ing .

The STYCAR tes t

This name is an abb reviat ion of Sheridan ' s Te st for Young Children and

Retardate s $ and comprise s a series o f t e s t s devi sed by Mary Sheridan which

supp ly informat ion ab out the child ' s percep t ion o f shape , it s visual acui ty

( to some ext ent ) and it s f ie ld o f vi s ion . The te s t should be conduct ed by

a pro fes s ional team , and the team should b e supp lied with an exhaus t ive

guide . (Page 46 )

(a ) Sheridan ' s toy te s t i s used at long range . I t inc ludes a serie s of

fairly large and small toy s respec t ively which the child can be asked to

ident ify or to mat ch with s imilar obj ect s (doll , car , aeroplane , spoon ,

fork ) . The fork and spoon can be used for roughly gauging vi sual acuity .

They have to be kept agains t a dark background . The large toys can be seen

by a child at vision level 1 ( see page while the smaller ones require

vis ion leve l 2 and ab ility to di s t inguish be tween fork and spoon at 4-5

metre s sugge s t a vi s ion level o f 3—4 . Thi s te s t make s a good int roduc t ion

to o ther te s t s and i s a use ful means o f arous ing intere s t .

Ill . 1 3 . The STYCAR toy t es t

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Ball on a rod . A dark screen can be used in this t e s t , which is performed

at various dis tances . Somebody s tands behind the s creen and moves white

balls , secured to a rod , from various po s it ions at the s ide s of the s creen

towards it s centre . Here again one ob serve s when the child fir s t no t ice s

the ball , i . e . fo cuse s on it and follows it s movement inwards . An o ther

vers ion i s to s tand behind the child and move the balls forward from var

ious direct ions . This te s t provide s some indicat ion of the child ' s f ie ld

o f vi s ion but require s quit e a lo t o f co—Operat ion from the child .

Ill . 1 5 . Ball te s t ,

using a ball se cured

to a rod The child

is o ccupied with

something , but the

occupat ion mus t not be

too enj oyab le and

ab sorb ing .

The b all te s t can be us ed from a mental age o f 6-8 months . It can of ten

supply good informat ion abou t the child ' s leve l o f vis ion . Low vis ion or

pronounced re tardat ion can make it hard to cap ture the child ' s interes t

with balls , which are no t part icularly amus ing unle s s the child can cope

with the game o f $ fe t ching the ball $ .

( c ) Sheridan ' s le t t er te s t also forms part o f the S t yca r serie s . This

include s whit e p las t ic le t t er s of the alphab et which are symme tr ical in

shape (A , H , 0 so that the child will no t have to j udge direc t ions

(right-lef t ) . There is al so a mat ch card showing various numb ers o f thes e

let t ers (5 , 7'

cnr 9 per card ) . The long-range and clo se—range te s t cards

disp lay individual printed le t ters which h av e. 1x ) be mat ched with p las t ic

let t ers or le t t ers on a mat ch card . The child can po int to a le t t er or

name i t . Thus the te s t doe s no t require the child to recognise the le t

ter s , only to ident ify the shape o f the symb ol and po int to a s imilar

shape .

Ment ion can also b e made at this po int o f Sheridan-$ ardiner ' s t e s t , which

represent s a further deve lopment o f Sheridan ' s le t ter t es t . In addit ion to

a t e s t card and mat ch card , thi s tes t also inc ludes a serie s o f books o f

te s t le t ters to b e used in vis ion te s t ing at long and clo se range .

Sheridan ' s PANDA te s t is modif ied for low vis ion . The te s t card s here

cons is t of b lack card shape s with te s t le t t er s in raised whit e p las t ic .

BUST

BUST i s the name of a new tes t for children at early mental ages and is a

comb ined te s t o f form percep t ion and vi sual acuity . It is de s igned in such

a way that the demand s on the child ' s unders tanding of the image can be

varied , and also the demands made on it s visual acuity . The tes t can be

used as a game , played with in various ways and , f inally , used for direc t ly

te s t ing visual acuity . BUST cons is t s o f picture cards in playing card

form . There are two serie s of dif ferent s tandards o f dif f iculty . Each

series has four f igure s . The f ir s t is pic torially ea sy to unders tand and

recogni se , compris ing as i t doe s a cup , f lower , wheel and clock . The

se cond serie s is a lit t le more dif f icult $ glas se s , s c is sors , spoon and

fork . These pic tures are supp lemented by a series o f LH symbols $ a ring ,

a s quare , an apple enmi aa house ( see also be low) . Each pic ture is repro

du ced on a mat ch card and the corre sponding concre te obj ec t s also have to

be availab le ( serie s l

Very s imp le ident if icat ions can be performed with the p icture cards by

merely including a couple of very dif ferent f igure s . This makes it easy

for the child to mat ch obj ect and pic ture . Thing s can be -made more dif f i

cult by le t t ing the child choo se between picture s which are quite s imilar

( s c i s sor s-glas se s , wheel—c lo ck ) and more dif ficult s t ill by including many

f igure s in the game . The more ab s t ract LH pic ture s are for a further s tep

in development .

Ab ility to dis t ingui sh be tween spoon and fork depends on vi sual acuity , and

the te s t re sult tallie s c lo se ly with o ther visual acuity te s t data . Te s t s

us ing the LH p ic tures provide the safes t indicat ion o f visual acui ty .

The card s are de s igned in such a way that the per son leading the game can

see from the back of them which serie s each card b elongs - to and the s ize o f

it s symb ol . The p icture s come in 9 s ize s . The idea i s for the large s t of

them , with a lit t le prac t ice , to be vis ib le at vis ion level 1 . ( See page

46 , ref . A tab le for use in interpret ing the re sult s is supplied to

gether with the te s t material .

BUST has been te s t ed for some years by eye spe c ialis t s , educat ional is t s and

p sycho logis t s . I t works we ll with children who se mental age is b e tween 1 %

and 7 years . It provide s a new opportunity when children are $ di ff icult t o

te s t fo r examp le on account o f low vis ion , re tardat ion and also hearing

impairment , b ecause the f igure s are eas ily trans lated into s ign language .

The game can be played with parent s , at t endant s and children and at var ious

leve ls of diff iculty . In this way the child can be made familiar with the

figures and can learn to compare and mat ch p ic ture s .

Ill . 1 6 . The BUST symbo ls $ series 1 ( le f t ) and serie s 2 ( centre ) . Right

the LH symbo ls .

I ll . 1 7 . Ob j ec t s used in the BUST te s t .

Ill . 1 8 . The BUST t e s t . Two very dif ferent f igures ( top ) are eas ily

d is t inguished , but it takes more e f fort and a cer tain visual acui ty to

dis t inguish b etween the clock and the whee l .

Ill . 1 9 . The BUST symbo ls arranged as a line te s t .

The LH te s t

The LH te s t is used for b o th long— range and clo se-range te s t s . There are

long-range te s t cards and clo se— range tes t serie s showing the LH symbo ls

individually , in line s and in clo se group s (re semb ling the sequence o f

le t ter s in a word ) . There is a mat ch card for the child to point if he ha s

dif f iculty in naming the symbols .

The LH te s t has been de s igned with the fact in mind that form percept ion as

well as visual acuity plays a part in tes t ing . The te s t has been s tandard

i sed by comparison with E tes t s and it produce s very dependab le re sult s .

It can be used from age 3 year s , and given prac t ice it can also be used at

earlier ages .

Ill . 20 . Lef t and centre $ LH te s t s . Individual symbols and line te s t s

for long-range use .

Right $ LH c lo se-u p t es t s $ s ingle symbols and line te s t s . (h i the o ther

side o f the card , the symbo ls are disp layed in a group .

The symbols are shaped in such a way that correc t percep t ion of the pic ture

will depend on visual acuity . If acuity is poor , the child will see the

sybmo l in all four case s as a ring $ the di s t inct ive feature s of the symbo ls

the corners o f the square , the indentat ions of the apple , the pit ched

roo f o f the house fade f irs t , leaving t h e/

imp r e s sion o f a round f igure .

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F f ooks' tes t

F f ooks' t e s t is also a symbo l te s t , for bo th long-range and c lose—range

te s t ing . I t consis t s of the symbo l s o f a circ le , a square and a triangle ,

the illiterate E and alphabe t ical te s t s . F f ooks' symbols are printed

individually in b lack on a white cub e , in various s ize s on the s ide s o f the

cube ( there are two dif ferent cube s ) . They are also printed on te s t cards

bound together with tes t cards for c lose-range use . The mat ch symbo ls are

of b lack plas t ic and should be placed on a b r igh t ,su r f a ce . This te s t can

o f ten ident ify the vis ion level o f children who are dif f icult to te s t by

o ther me thods . The reliab il ity of the te s t is quit e low , s ince it is too

easy to dis t inguish the triangle and the other symbo ls by their shape

alone , without any need for good vi sual acuity . F f ooks' near vis ion tes t

include s bo th E symbo ls in c lo se groups , F f ooks' symbols and le t t ers of the

alphabe t . This is a very handy te s t to have availab le and is very suitab le

for rough te s t ing o f the child ' s level o f vis ion .

I ll . 2 1 . F f ooks' symbo l te s t . The book on the le f t contains bo th long

range and shor t-range te s t s . The near vis ion te s t contains the F f ooks

symbols , the illiterate E and le t ter s o f the alphabe t , all displayed in

group s .

Figure chart s

There are various type s o f f igure char t s depic t ing obj e c t s . Their disad

vantage is that they are unre liab le if the pi cture s are realis t ic . If they

are s tylised the child o f ten canno t unders tand what they are meant to de

pic t . The b igge s t disadvantage , espec ially in the case o f retarded child

ren , is that the char t s contain so many figure s . These children almo s t

invar iab ly f ind it dif f icult to cope with many picture s at a t ime . Con

s equent ly , p ic ture chart s are seldom a succes s . They can b e t r ied occas ion

ally , if i t is diff icul t t o ge t the child interes t ed in o ther t e s t s .

Os t e r b e r g's char t is used to some extent in Sweden . There is also a Danish

te s t which has acquired some currency , and an American te s t (Lighthouse ) .

Ryse r's pic ture te s t can be used at c lo se quar ters and made more intere s t

ing by pre sent ing real obj ec t s for matching .

I ll . 22 . Ryse r's p ic ture t e s t can b e comb ined wi th real obj e c t s .

Le t ter chart s

Ordinary le t t er chart s are known to everybody , and I shall no t cons ider

them here , b eyond ob serving that the te s t ing dis tance can very well b e

reduced when us ing them . Thing s can be n u de eas ier by s creening of f the

le t ters , e . g . us ing a cardboard mask with a window to iso late a line or

half a line , thus reducing the number o f le t ter s disp layed simultaneously .

There are also proj ec tors which disp lay only one or a few le t ters at a

t ime . Individual let t ers occur in the Sheridan-$ ardiner te s t cards . The

HVT chart contains only a few le t ter s and is s tandardis ed for a reading

dis tance o f 3 metre s .

Ill . 23 . The HVT chart and match cards . The chart is used at a dis tance

of 3 metre s .

Reading chart s , reading pas sage s

I t is also impor tant to te s t vi sual acui ty with reading char t s at c lo se

quar ter s and by means o f reading pas sage s . Here again , the te chnique and

text s have to b e modif ied when dealing with vi s ion impaired children . On

this subj ec t , re ference is made to the T— s cale , ob tainab le from RPH-SYN ,

So lna . English equivalent s include , fo r examp le , the Maclure reading types

for children (Clement Clarke , Lt d . , London ) .

Ill . 24 . The T- s cale , Tomteboda typographical t e s t s cale s , and Ma clure

Reading Type s for Children .

Mult iple disab ilit ie s

Mos t vis ion te s t ing methods are based on the child us ing hi s hearing , motor

skills and speech faculty in. tfl u 3 te s t s i tuat ion . Consequent ly , children

with mult iple disab ilit ies are dif f icult to te s t .

Speech prob lems . If the child has no speech , a te s t can be used in hh ich

one po int s at things ins tead o f naming them . The child can also be allowed

to answer by making various ge s ture s . In case s o f this kind , behavioural

observat ion is important , and in this way informat ion is ob tained about the

child ' s vis ion without the child having to speak .

Deafnes s hearing impairment is a dif f icult prob lem in the te s t ing situa

t ion . Even if one knows a certain amount o f s ign language , help is s t ill

needed in communicat ing with the child , pr imarily in order to explain

vi sual games and tes t s p roperly . Behavioural ob servat ion has it s appo inted

p lace and can yield good re sult s , e spec ially if the child has a fairly high

level o f vis ion , so that he will b e act ivated by visual obj e ct s .

Severe mo tor disab ilit ies are quite f requent . This po se s a serious prob lem

when apprais ing vis ion , because the child is unab le to show , by turning his

head or reaching towards a visual obj ect , that he can see things . No r is

he ab le to point in ordinary vis ion te s t s . It is no t uncommon for these

children also to lack speech , in which case there can be no ques t ion of,

their expre s s ing verbally what they can see either . All that remains is to

read o ff the child ' s emo t ional ut t erances when confronted by visual ob

j e c t s . If the o culo-mo tor skill s funct ion , the child ' s vis ion can b e

as se s sed by means o f hi s ab ility to fo cus on obj e ct s and follow them with

his gaze .

CHART

Leve l Visual achievement

o f

vi s ion

I Recognis ing peop le and

II

I I I

IV

( 1 )

face s at c lo se quarters .

Big toys , dolls , so f t

toys , balls , tab leware ,

feeder bo t t le , cut lery ,

furniture , c lo thing .

Locomo tor vis ion , dif fer

emees o f level dif f icult .

Ball game s usually impo ss

ib le

Small toys . Marb le s and

balls . J igsaws , large

pic tures . Card games .

Lego . Rais ins , f lakes ,

smart ie s .

Lo comotor vis ion quite

good . Ball games may b e

doub t ful . Cyc ling of ten

po s s ib le . With visual

tasks a t clo se quarter s ,

$ close-peering behaviour .

Very small t oys and ob

j ec t s . As semb ly kit s .

De tails of p ic tures , wood

en beads . Needlework

( large s t it che s ) . Hun

dreds-and-thousands ,

crumb s . Le t t ers o f the

alphabe t , f igure s (no tsmall print ) .

$ Close—peering $ b ehaviour .

Can ' t see car regis t rat ion

numbers at a dis tance .

S it s c lo se to the TV , has

some troub le see ing the

b lackboard at s chool .

Reads ordinary te s t atnormal working dis tance .

Wat ches TV and can see

the b lackboard .

3-4 metre s

$uite good ,-O. 3

but no

de tails at

a dis tance .

No t no t ice

ab ly reduced

Some f ocus ing

capacitynece s sary .

Fo cus ing capacity

and accommodat ion

nece s sary .

Impairment no t

very not iceab le

be fo re s chool age

if vision is

o therwise normal

( 1 )

Mo re than There may s t ill be

vis ion impairment

if cont ras t vi s ion

is reduced o r

there are great

o culo—mo tor prob

lems . ( 1 )

Severe re s t ric t ions of the f ield o f vis ion af fe c t vi sual achievementat all leve ls o f vis ion .

have an affec t .

Bad night vi s ion or adap t ion prob lems also

Vi sual Approxima te Remarks

sphere visual

acuity

Po s s ib le with

met res peripheral vis ion

without f irm

focus ing , g iven

reasonab ly goo d

cont ras t vis ion .

Reference s

l . Hyvarinen L , and Linds t edt E .

As se s sment o f Vi sion in Children . SRF Tal o . Punkt, 1 98 1 ( Sands

bo r gsv . 52 , 8— 1 2 2 88 ENSKEDE , Sweden . Price c . 84 . I O$ )

2 . Linds tedt E , and Hyvarinen L .

$ U ST -LH playing car ds$ M AN UEL . S tockholm 5

(EL I SYN , Eva Lind s ted t , Hogbe r g sg . 30 , 8- 1 1 6 20 STOCKHOLM , Sweden . )

3 . Nielsen Lillie $ The comprehending hand . Nat ional Board o f So c ial

Welfare , Copenhagen 1 9 7 9 .

4 . Sheridan MD $ Ma nual for the S t yca r Vi s ion Tes t . NFER Pub lishing Co . ,

Windsor , 1 9 76 .

5 . Hyvarinen L and Lin ds t ad t E Early Vi sual Development normal

and abnormal .

Ac ta Oph t h a l , supp l . 1 47 , 1 983 .

No te .

Mo s t o f the t e s t s ment ioned in this b ook are availab le through

Clement Clarke Ltd 1 5 Wigmore S tree t , LONDON WlH 9L . Engl and .

The S t yca r se t through $ Pub lishing Co . , WINDSOR , England .

The BUST and LH—p laying cards through $ EL I SYN , Eva Linds tedt , Hogbe r gs

gatan 30 , S-1 1 6 20 STOCKHOLM , Sweden .

The LH te s t s through $ Vis t e s t , Lea Hyvarinen , Ha rma apa a r anku j a 3 , SE—02200

ESPOO , Finland .

Translated by $ Roger $ . Tanner .

Copyright $ Eva Lind s tedt . All right s re served .

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