Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)
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Ophthalmic Physiol Opt · Oct 1994
Randomized Controlled Trial Clinical TrialDouble-masked placebo-controlled trial of precision spectral filters in children who use coloured overlays.
We selected 68 children who reported benefit from individually chosen sheets of coloured plastic placed upon the page when reading, and who used these regularly without prompting. These children viewed text illuminated by coloured light in an apparatus that allowed the separate manipulation of hue (colour) and saturation (depth of colour), at constant luminance. Many of the children reported improvements in perception when the light had a chromaticity within a limited range, which was different for each individual. ⋯ The children kept diaries (36 completed) recording symptoms of eye-strain and headache. The children and those responsible for their assessment were unable reliably to distinguish 'experimental' from 'control' lenses. Nevertheless, symptoms were less frequent on days when the 'experimental' lenses were worn (P < 0.003).