Develop. Med. Child Neurol. 1913, 15,437-440

A Colour Vision Test for Young Children and the Handicapped

Peter Gardiner

Introduction Testing for colour vision has always

been difficult because there is a dilemma whether to test deeply and scientifically and thereby to identify the exact anomaly present, or to confine the question to whether colour confusion is likely to arise in a person’s life or occupation and, if it does, what importance should be attached to the defect exhibited.

It seems true that most people with a defect in colour judgement adapt well, except in situations which do not allow other clues. Brightness or expected posi- tions, as in traffic lights, do provide these clues, but navigation lights may not.

Exactly when or how this adaptation to colour discrimination difficulties takes place is not known, which is a situation parallel to all other adaptations eventually made by children with visual problems. But there is one big difference; as far as we know, colour discrimination is a developmentally inherent ability and, apart from the adaptation necessary to compensate for any defect, is a basic component of a child’s equipment.

It is possible that in the child’s early years while he is still in the process of adapting to a defect in colour discrimina- tion, the defect may be a handicap, particularly at school. We do not know

this for sure, but there has been a report of a teacher telling a child he is stupid to paint leaves red, though no doubt if he were an avant garde painter he would be praised for it ! There have also been reports that young children with colour difficulties very soon become aware of disapproval and ‘cover up’, as we all do in the face of a personal problem which the majority of other people don’t seem to understand. Most of us do this very successfully (but no more so than a child) by altering the way we present our difficulties in a more understandable context. Thus income tax intricacies present as headache or ‘eyestrain’.

It therefore seems reasonable that the presence of normal colour vision should be determined as early as possible and certain- ly earlier than has been usual hitherto. With this in view, a test has been devised which will identify colour discrimination deficits in children at school-entry age (age five in the U.K.). Like the Ishihara tests, it is directed towards finding anomalies of red/green discrimination, which are by far the most common, but the test does not help to identify the extremely rare blue/ yellow anomalies.

The test is an amalgam of the Sheridan- Gardiner matching test for visual acuity and other standard colour vision screening

Research Fellow in Ophthalmology, Guy’s Hospital, London SEl.

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techniques. It therefore naturally follows on after an examination of visual acuity. With efficient organisation it can be performed with normal children in about two minutes, though handicapped children, whether defective physically, visually or mentally, may take a little longer to test.

Material and Procedure A booklet of eight coloured plates

is provided; the first two plates indicate whether the child understands the method, the other six each show a different colour-confused letter. Six cut-out plastic letters are also provided; these are placed in front of the child and he has to indicate which letter he sees in the colour-con- confused plate (Fig. 1). The child is matching patterns, not recognising and naming letters. Virtually no manual dex-

terity, no literacy and no speech is needed. If a colour or other defect is present, then ‘wrong’ letters are chosen.

The printed instructions for the test may require amplification. It is extremely im- portant that there should be no chance of one child copying the preceding child’s performance. The examiner must hold the book vertically, it must be well illuminated, and at a distance not less than two feet (60cm) and preferably not more than four feet (120cm) from the child. The cut-out plastic letters are arranged on a table in front of the child in random order, each the right way up and within easy pointing distance. Touching the letter being shown is as acceptable as picking it up. In practice, plate 5 produces the most difficulty, as the sophisticated child may call it ‘B’ (instead of P). It is therefore necessary to ask and to

Fig. 1.

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insist that he selects one of the cut-out letters displayed. The defective child, however, does not have this problem.

There are three possible answers: (1) ‘correct letter identified’, which is entered as ‘V’ on the record slip provided; (2) ‘defective’, where the alternative letter correct for red/green colour defect is identified, and is entered as ‘X’ on the record slip; and (3) any other response, which is entered as ‘(2‘. The child with a colour defect who is likely to have any real difficulty at school will certainly get a majority of ‘X’ answers. In the age-group we are discussing (five years), there are bound to be a group (perhaps 5 per cent) of children who introduce several, but not a majority of, confused answers. The interpretation of these is interesting, but such responses are usually not relevant to colour defect.

As a by-product, the test also gives extra information-for example, clues as to those children who may have perceptual difficul- ties or cultural problems, who will be more hesitant and give more ‘confused’ answers than do children without these handicaps.

In a small minority of children the first two letters may not be selected correctly; when this happens, the test should be abandoned and repeated when the child is older. In a pilot study of 120 five-year-old boys of mixed countries of origin, a definite answer was obtained in well over 90 per cent, and in fact none failed to understand the method.

If children younger than five are to be tested, the two opening letters ‘M’ and ‘A’ (which do not reappear in the plates following) could be removed after they have been used to begin the test, in order

to simplify the choice by having only four instead of six letters to choose among, but this is undesirable as a general practice with children aged five or more.

Discussion The test has the same scientific limita-

tions, as has, for instance, the standard Ishihara; however, it does have the advan- tages that no literacy of any sort is required, and there is less ambiguity in the answers obtained because there is no manual dexterity involved. It has an additional advantage over the children’s Ishihara in that more choice is available and that the use of letters is similar to the other tests to which the child has already been exposed. With all children of all ages it is important to stick strictly to a ‘matching’ technique and not to ask the child to name the letters.

The primary object and usefulness of this test therefore is for screening purposes. It offers an opportunity for all school entrants to have a routine screening examination of colour discrimination ability, just as they do of their visual acuity, with the result that teachers can be in- formed of possible limitations in a child’s school performance. Because of the in- creasing use of colour in primary education, such information may now be more important than it has been previously. It is hoped also that to investigators of percep- tual and genetic problems, the test may be of some help at an earlier and more informative age than previously.

The test does not need trained personnel, is easily portable and, apart from requiring lighting as near daylight as possible, it can be performed anywhere and takes only a short time.

SUMMARY

A test devised to identify children with a colour discrimination defect at school-entry age (age five in the U.K.) is described. The test does not require trained personnel, is easily portable, and takes only a short time to administer.

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RBSUMB Test de vision des couleurs pour jeunes enfants et handicapks

L'auteur dtcrit un test destine B identifier les enfants presentant un trouble de la discrimination des couleurs B l'bge de dCbut de la scolaritt (5ans en Grande Bretagne). Le test ne demande aucun personnel specialist, est facilement transportable et ne demande que peu de temps.

ZUSAMMENFASSUNG Ein Farb-Seh Test fur Kleinkinder die Behinderte

Ein Test wird beschrieben, der entwickelt wurde, um Farbfehlsehen bei Kindern im Einschulungsalter ( 5 Jahre im U.K.) herauszufinden. Der Test erfordert kein geschultes Personal, er ist leicht zu transportieren und bedarf nur eine kurze Zeit zur Anwendung.

RESUMEN Un test para verijicar la capacidad de ver 10s colores en nifios y atrasados

Se describe un test inventado para identificar a 10s niiios con una discriminacih defec- tuosa de colores a la edad de entrar en la escuela (cinco aiios en el Reino Unido). No hace falta persona especialisada para administrar el test, que es facilmente portitil y puede realizarse en muy poco tiempo.

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