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A protocol for the measurement of Eye Dominance in young children

A protocol for the measurement of Eye Dominance in young children

INTRODUCTION

Research in sport has shown that eye and hand coordination is a function of the two primary components of visual performance i.e Aiming(focusing & convergence) and Anticipation (depth perception, binocular vision). The only thing that distinguishes sports from any other occupation is the level of the visual demand which is at its most extreme in competitive sports. These two primary components of visual demand are at its most extreme in competitive sports.

These two primary components of visual performance are also essential pre requisites of ability to read and write. The newly born child begins to use aiming as soon as they become visually aware. The first object they reach out to touch, requires their right hand to be in line with the aiming eye and the object to which they are reaching out. If there is a problem with eye dominance, the object won’t be in the place where they anticipate it to be. The child will not be frustrated by this phenomenon. His developing brain will accept it as normal and will make necessary adaptation and corrections. The indication of this may be that the child may take longer time to find the object. This could take a more dangerous shape when the child begins to walk and move around the room.If they misjudge the position of sharp table and chairs edges,then they tend to walk into these instead of avoiding them, leading to profound effects on their mobility and confidence. This could be in just the same way that the sporting visual development is inhibited by poor visual judgement.The physical development of the growing child will be inhibited.This is typically what happens in dyspraxia. When it comes to a finer level, i.e in learning or reading, a stable aiming eye required to hold the visual system steady. If there is a dominance conflict then attention jumps several words, even several lines and affects comprehension.This is a simple behaviour of dyslexia. And when this effect manifests as reading or mobility difficulties in children, the behavioural effects are lasting and profound. Since the treatment before the age of 2 is more effective than later ,a comprehensive eye screening should occur before school age is reached,possibly as early as 6 months to 12 months.

Establishing which eye is dominant plays a vital part in a binocular vision assessment.A study has shown poor stereoacuity in Type 11 group.Research has also shown that binocular instability plays a part in dyslexia.It stands to reason that a young child with accommodation and convergence problems coupled with poor pursuit movement will have problems learning to read and write.The dyslexic will likely to have a phonological deficit in association with visual anomaly.

The overall conclusion from this is that as in sport vision screening, the ocular dominance is very important,so is the case with the ability to read and write of a child. Having established the ocular deficiency the measures can always be taken to correct it.

MEASURING DOMINANT EYE OF YOUNG CHILDREN

In examining the eyes and vision of pre school children, the approach and method have to be modified from the routine appropriate to older children and adults.Very young children can be wary of new situations and environments and will also have a much shorter attention span. Precise measurements may not be possible and needs to look for significant departures from the normal. We are more reliant on objective tests as very young children are unable to give subjective symptoms and responses

Impression of the parents

Impression of the parents are invaluable, in order to measure the eye dominance in young children.Parents should watch for some tale tell signs of possible visual behaviour, the information regarding those can be taken from them. An information about holding the pencil in a particular hand, using the hand for eating, closing or covering one eye to observe any object, rubbing of eyes, attention span, placing the head close to the book while reading, loosing pace while reading, turning or tilting the head to one side may give us certain visual clues.

Hand dominance

In a situation where one hand is only used, we will see the preferred use of the hand by the children. This could be confirmed by telling the child to draw or scribble and observe which hand was used.The child declares his hand dominance subjectively like this.

Foot dominance

A set of footballs can be used. Children can be presented with a set of footballs at a particular distance and in front of them and may be asked to kick each ball at a time and their preference of foot can be observed subjectively.

Although Hand and Foot dominance are not the clear indications of ocular dominance,it helps to categorise them in Type 1 and Type 11 category.

Eye dominance

Assessing the eye dominance in a very young child involves a significant amount of challenge and patience on the part of the observer.The procedure selected has to be instant and interesting to get the proper results.However the following procedure may be tried to assess the dominant eye-

1. The child may be presented a card with a 25 mm hole and is instructed to hold it out in front of him at a comfortable arm’s length to view the practitioner’s nose through the central circular aperture.Eye seen by the practitioner is recorded and is considered as dominant eye.This may also be a gross test to assess the presence of binocular vision.Any other person apart from the child,holding the card in front of the child will defeit the purpose of the test.

2. A cone made of paper having a length of 30 cms may also be used.The child looks through the larger aperture down the cone through a 25 mm hole at the other end of the cone and fixates on the practitioner’s nose.The practitioner wear a red clown’s nose to encourage the fixation and stands 3 m from and in front of the child.The preference of the eye is recorded as dominant eye.

3. A child can be asked to form a small hole between his hands by placing right hand over left hand forming a small hole between thumbs and index fingers and is asked to view the practitioner’s nose through the aperture while his arm’s are outstretched.The practitioner stands 3 m in front and away from the child and records the sighting eye.The test is repeated three times.Second time with left hand over right and then right over left.

CONCLUSION

The measuring of Dominant eye in young children seems to have a little different approach than that of the adults. In reality the children are subjectively non-responding and their visual attention is very short So the procedure for measuring the dominant eye has to be more interesting and attention catching. For example
instead of using any object, a colourful photo frame of any tattoo or cartoon can be used which may be placed a few feet away from the children and he may be asked to look at the centre of the object in the photo through the centre of the triangle made using both the hands.

The detection of ocular dominance may help to design a better visual behavioural pattern.