People with specific learning difficulties have problems with certain skills at school. The most common type of specific learning difficulty is specific reading difficulty; and this is often called dyslexia. Dyslexic children are usually poor at spelling and may seem intelligent in conversation, but have trouble with written language. Leonardo da Vinci and Einstein are both thought to have been dyslexic.
Dyslexia is best diagnosed by an educational psychologist who, in addition to other tests, will calculate a person's expected reading age from their intelligence and age. The difference between this and the actual reading age, as measured with a reading test, gives a measure of the reading difficulty. The term dyslexia is usually reserved for a severe degree of reading difficulty. Psychological assessments can be arranged through your school, or privately through an organisation called Dyslexia Action.
The term dyslexia is used throughout this leaflet, but the visual problems that are described can also be present in children who have other, non-dyslexic, difficulties at school. A person does not have to be diagnosed as dyslexic in order to benefit from the tests outlined here.
Most experts agree that problems with sight are not usually
a main cause of dyslexia. Certain visual problems, however, do occur more often
in dyslexia and these may, in some cases, contribute to the reading difficulty.
These visual problems would not normally be detected in a
school eye test. Two of the most
common visual anomalies in dyslexia are a reduced ability to focus close to and
poor or unstable co-ordination of the two eyes (binocular instability). These
visual problems can cause eyestrain, visual distortions, or headaches. This may
slow reading and discourage children from prolonged reading.
Not all dyslexic people have these visual problems, but some have visual anomalies without realising it. People with a mild specific learning difficulty, perhaps not bad enough to be called dyslexia, can also have these visual problems. These problems might cause difficulties in perceiving the correct order of numbers as well as letters on the page. For some people, this might contribute to difficulties with mathematics. The visual problems can usually be treated with simple eye exercises. In some cases, glasses may be prescribed.
An eye examination with an optometrist will not be able to diagnose dyslexia. But if dyslexia is suspected then it is sensible to start by investigating whether the visual function is normal.
Our principal optometrist, Professor Bruce Evans, has been described as “the UK’s foremost expert in the area of visual correlates of dyslexia”. Professor Evans’ doctorate was on this subject and he frequently lectures on this. His research has been published widely, including a book for teachers, psychologists, and parents called Dyslexia and Vision. For more information on (or to buy) this book, click on Dyslexia and Vision .
Professor Evans is able to see
patients at the practice to carry out a full eye examination and specific
additional tests to look for the visual problems that may be associated with
difficulties at school. These appointments usually take about 1 hour. The fee
for the examination with Professor Evans is £106.50 for children and £117.00
for adults.
These fees include a report explaining Professor Evans’ investigations, results, and recommendations. Many tests are necessary at the first examination but it is not usually appropriate to repeat all of these at subsequent consultations.
If you would like to arrange an appointment with Professor Evans, please telephone our reception and ask for a special investigation for the assessment of visual aspects of specific learning difficulties.
Some people
with dyslexic difficulties benefit from using coloured filters.
If our
findings suggest that a person may benefit from colour, then we will issue them
with a coloured overlay to try. If this is still being used after one school
term then a further appointment can be arranged for testing with a new
instrument, the Intuitive Colorimeter (illustrated on the left). This enables
the precise tint for glasses to be determined. The charge for this further
investigation is £45.
For patients who are prescribed Precision Tinted lenses the exact colour of tint that is required can, like any other optical prescription, change over time. Therefore, we usually repeats the testing with the Intuitive Colorimeter at yearly intervals.
The British Dyslexia Association is a support group which can give information on the legal situation concerning learning difficulties and legislation on education. Their address is 98, London Road, Reading, Berks., RG1 5AU.
Dyslexia Action has many local offices where psychologists can assess learning difficulties and specially trained teachers can help to overcome these problems. Their head office address is 133, Gresham Road, Staines, TW18 2AJ. The address of their local centre in Essex is Chelmsford Dyslexia Action, 137 New London Road, Chelmsford, Essex, CM2 0QT.