Coloured Filters for Visual Stress—Early Studies

The historical background to the use of colour in assisting with reading is summarised in this chapter. Recent developments in the optometric use of coloured filters were facilitated by modern techniques for tinting plastic ophthalmic lenses. These techniques permit the selection of coloured lenses defined by a spectral transmission that suits an individual. The two new systems developed to use this technology in the 1980s for precision tinted lenses are described, together with associated developments in the Intuitive Colorimeter system, Intuitive Overlays, and Wilkins Rate of Reading Test.