A PRELIMINARY INVESTIGATION INTO THE ETIOLOGY OF MEARES-IRLEN SYNDROME

A recent double-masked placebo-controlled trial has confirmed that som e children experience a reduction in symptoms of eyestrain and headach e when they read through individually prescribed coloured filters and has shown that this benefit cannot be solely attributed to a placebo e ffect. People who are helped by coloured filters in this way have been described as having 'Meares-lrlen syndrome'. We investigated the mech anism of this benefit by studying the optometric and visual perceptual characteristics of the children in the double-masked study. This popu lation had normal refractive errors and heterophorias (none of the sub jects had strabismus). They demonstrated slightly, but significantly, reduced amplitudes of accommodation and vergence and poor stereo-acuit y. However, these factors seemed to be correlates of Meares-lrlen synd rome rather than the underlying cause. Pattern glare, a sensitivity to striped patterns (e.g. lines of text), was prevalent in our sample an d was significantly associated with the subjects' symptoms, The spatia l contrast sensitivity function was normal. Copyright (C) 1996 The Col lege of Optometrists. Published by Elsevier Science Ltd.