Ophthalmic Physiol Opt. 1996 Jul;16(4):286-96.
A preliminary investigation into the aetiology of Meares-Irlen syndrome.
Evans BJ, Wilkins AJ, Brown J, Busby A, Wingfield A, Jeanes R, Bald J.
Institute of Optometry, London, UK.
A recent double-masked placebo-controlled trial has confirmed that some children
experience a reduction in symptoms of eyestrain and headache when they read
through individually prescribed coloured filters and has shown that this benefit
cannot be solely attributed to a placebo effect. People who are helped by
coloured filters in this way have been described as having "Meares-Irlen
syndrome'. We investigated the mechanism of this benefit by studying the
optometric and visual perceptual characteristics of the children in the
double-masked study. This population had normal refractive errors and
heterophorias (none of the subjects had strabismus). They demonstrated slightly,
but significantly, reduced amplitudes of accommodation and vergence and poor
stereo-acuity. However, these factors seemed to be correlates of Meares-Irlen
syndrome rather than the underlying cause. Pattern glare, a sensitivity to
striped patterns (e.g. lines of text), was prevalent in our sample and was
significantly associated with the subjects' symptoms. The spatial contrast
sensitivity function was normal.