Coloured Overlays + Meares–Irlen syndrome

Coloured overlays are sheets of translucent or transparent coloured plastic that can be placed over a page of a book.
Coloured overlays reduce the perceptual distortions of text that children sometimes describe. They enable some children to read text more fluently and with less discomfort and fewer headaches. Each individual seems to need a different colour, so it is important to assess the effects of a wide range of colours.
In several studies, children in county primary schools were individually shown a passage of text covered in turn by a variety of coloured overlays, including grey or clear overlays for comparison. About 20% of the children found one or other of the colours improved the clarity of the text. They continued to use an overlay of that colour without prompting for more than three months. They read more quickly with their overlay, both before and after they had become accustomed to its use."