The use of selective contrast colour filters for eye disease

Ian Pyzer describes the research about the use of colour filters in the management of visually impairing eye disease

For some time the use of contrast enhancing colour filters has been identified as a way of attempting to improve visual performance to a broad selection of patients with anterior segment eye disease.

As high contrast filters absorb short wave blue light, often below 520nm, this results in a relative increase in the ratio of yellow to red visible light being transmitted. With the eye's photoreceptors' peak sensitivity being at 555nm, the resulting retinal illumination is accentuated, providing, in effect, an increase in image contrast.

With their selective filtering of blue light, these high contrast filters are often alternatively referred to as 'blue blockers'.

Aside from taking a look at a selection of the filters available and reviewing what methods can be used to evaluate them, this article will also deal with the question of whether they might be used to help slow the decline in visual function for individuals with degenerative retinal conditions, or delay the onset.