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.

One of the most common visual anomalies in dyslexia is poor or unstable co-ordination of the two eyes (binocular instability). This can cause eyestrain, visual distortions, or headaches and may slow reading and discourage children from prolonged reading.

The use of coloured filters is a controversial topic, and it is widely agreed that coloured filters should not be thought of as a treatment for dyslexia. About one in five people with dyslexia may also have a co-occurring condition that causes them to experience visual distortions (e.g., words appear to move or blur) and/or eyestrain and headaches from a page of text. Some of these children report a reduction in their symptoms with coloured filters, and this condition has been called Visual Stress (also known as Meares-Irlen Syndrome, Irlen Syndrome, or Scotopic Sensitivity Syndrome).