One of my patients, a 10-year-old boy has been advised by his teacher to have an eye examination. He is an intelligent pupil when it comes to verbal school work but when it comes to reading he struggles. The teacher has estimated that the boy reads at the level of a 7-year-old? What should I do?

Sadly, there are many children and young adults who struggle with reading. This of course prevents them from reaching their full educational potential. There are many adults who struggle to read because they had problems when at school and this is likely to prevent them from reaching their full work and life potential.

Some people have dyslexia. This is caused by misconnections in the brain which occurred during embryo development. A person with dyslexia and no underlying eye problems or perception problems cannot be helped by eye specialists and need the help of educational specialists.

Some people with reading problems complain of wavy lines of print, words floating, blurred print, the gaps between words being more obvious than the words, the page being too bright and words changing size, of words coming and going when looking at the print which would appear as standard print to a good reader.

These symptoms can be called perceptual distortions. They do not exist on the page but are perceived to exist by the underachieving reader.

The problem for the eye specialist is that the perceptual distortions can be caused by uncorrected refractive error, binocular vision problems or pattern glare or any combination of these. The other complicating factor is that these symptoms may also be present in someone who has dyslexia.

Uncorrected oblique astigmatism may cause lines of print to look wavy.

Uncorrected hyperopia may cause blurred print and/or words to change size as accommodation is engaged and then relaxed.

Convergence insufficiency can cause floating or moving words.

Low accommodative amplitude can cause blurred print and/or words to change size.

Pattern glare may cause all the perceptual distortions highlighted above.

People with dyslexia may also have uncorrected refractive error, binocular vision problems and pattern glare.

Pattern glare is a reaction to the pattern print makes on a page. It is a series of black and white lines just like a contrast sensitivity grating. Many people perceive distortions when viewing a series of high contrast closely spaced lines. Some people are extra sensitive to this pattern and experience perceptual distortions when looking at print on a page.

When presented with a person who is underachieving with reading the eye specialist should undertake a sequential process. Firstly, looking for uncorrected refractive error and although rare, ocular disease. Secondly, a binocular vision workup looking for problems with convergence and accommodation. Thirdly, looking for pattern glare.

It is possible that prescribing glasses and/or treating a binocular vision disorder is enough to prevent the perceptual distortions. If all eye problems have been treated and some perceptual distortions remain then it is necessary to treat the pattern glare.