Visual Problems & Dyslexia
Eye problems themselves are not a cause
of dyslexia, however they can be a contributory factor to the reading
and writing difficulty.
There
are two particular visual problems that seem to occur more often in
dyslexics than in non dyslexics:
1.
Difficulty maintaining focus at near tasks
2. Poor co-ordination of the two eyes
Because of this it is important that those who
have the symptoms of, or are assessed as having a specific reading
difficulty, undergo a
Pre-Overlay Vision Assessment to check for the above two anomalies.
Pre-Overlay Vision Assessment:
This is a detailed investigation that is concentrated
on checking near vision focusing and co-ordination.
It is preceded by a standard Eye
Examination.
The assessment checks for:
Latent Hyperopia (long sightedness):
drops are instilled which prevent the focusing muscles from temporarily
working for a few hours. This allows any residual hyperopia to be
unmasked. Moderate and large degrees of latent Hyperopia can be missed
during a routine examination, particularly in young children, as they
are able to mask it due to very active muscle activity.
Accommodative Insufficiency:
The eyes ability to change its internal lens power (accommodate) is
measured. An inability to accommodate or maintain accommodation will
lead to near vision fatigue and blur.
Binocular Co-Ordination:
if the two eyes do not work in conjunction with one another a binocular
instability is said to be present. Co-ordination
problems are fairly common, but are frequently missed. Measurement
of the severity and type of instability is undertaken and a treatment
plan is formulated to correct or manage it. Most binocular co-ordination
problems respond well to a combination of eye exercises, spectacles
and prisms.
The correction of any underlying visual problems can often dramatically
reduce symptoms in many individuals who are struggling with reading
and writing. However those who are still having difficulties, or those
in whom the pre-overlay Assessment did not identify any anomalies,
are recommended to have a Coloured
Overlay Assesment. |
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