All Posts Tagged Tag: ‘amblyopia’

A child wearing a patch

Squints, turns and lazy eyes.

I had a young boy in for an eye exam today, booked in because he had failed his school vision screening. When his mother booked the appointment, I got the impression that she thought that his eyes were fine, except for the fact that he has a squint, “but he has always had a squint.”

Any optometrist’s immediate thought would be that a squint would be an obvious fail on a school screening, as squints are not normal. Some squints might not be easily detected at a screening- sometimes squints can be very difficult to detect without experience, but what is detected is the lazy eye which usually results from the squint- if a child learns that they can see better with one eye than both together (as two misaligned eyes cause double vision, and confusion- an inability to tell which object is in the straight ahead position), eventually the brain might habitually ignore one eye, and it will become “lazy”.

A squint is not the only possible cause of a lazy eye – if there is a significant difference between the sharpness of the eyes, again the brain might ignore the blurred eye. This is less common than a squint as the cause of a weakness, but often there is no way the parents could possibly suspect that there might be an issue.

Lazy eyes need to be detected as young as possible (ideally they should be prevented)- even if the bad eye cannot be improved to the same standard as its fellow, any improvement which can be gained (usually quite quickly – as a young child) may prevent months or years of difficulty as an adult, who may be unable to work or drive if the good eye was damaged by accident or disease. Lazy eye treatment may also remove restrictions which might be imposed in certain career choices, such as those requiring Class 2 driving licences, and many of the forces.

I had reason to contact Meath County clinic about this young chap, and was informed that there was an approximate waiting list of at least 12, probably more like 18 months before he could be seen –  this is unacceptable, as a problem like this will be much more difficult to fix by an age of seven. He will be 6 to 6 1/2 when he is eventually seen. There is no point in screening the vision of school children if there is no sensible referral pathway available for those who fail.

This post is just to mention to parents that even if you THINK you see your child’s eye turning (perhaps it may be more obvious when they are tired) or you suspect one eye is poorer than the other, you should get this checked out as soon as possible – it is not normal, it will not go away on it’s own, and it will almost always result in a poor eye if nothing is done to intervene. Children rarely complain about visual difficulty – they have no reference to know that having a poor eye is not normal.

Parents – it is up you you!


Lazy Eye Treatment – using video games!

Treatment for lazy eyes has for years focused on patching the good eye to force the brain to use the weaker eye. This does work, particularly when the lazy eye is caught at a young enough age – by 7 or 8 years of age, the visual system is adult like and pretty much fully developed. At this age, patching needs to be done more aggressively, the improvement is often slower, and the result less effective than in a younger person.

Patching forces the brain to pay attention to the lazy eye, but only when the good eye is wearing the patch- as soon as the favoured eye is uncovered, the brain will usually revert to ignoring the lazy eye.

Recently scientists is two centres have found that video games, which have been adapted to show part of the display to one eye and other parts to the other eye are showing a remarkable improvement over traditional methods. For example the Canadian team used a modified Tetris game, where the blocks which had fallen were visible with one eyes, but the falling block was only visible with the other eye- this would require both eyes to work together to have any chance of a decent score.

Any video game type could be adapted – a racing car visible to one eye, the track only visible to the other eye.

These have the advantage of trying to train the brain to use both eyes at the same time, something that may continue after the “therapy” is over, which is not the case with traditional patching.

With early findings such as in these studies, more research is necessary, but there may in the near future be another better treatment for lazy eyes- another study in 2011 found that there was a marked improvement, even in adults with only 40 hours of game time. This study was gaming with patching – perhaps gaming without patching would be more effective.

BBC report on the Canadian Study and the Glasgow Caledonian Study– again reported by the BBC.

Local eyecare for all the family