A double-masked randomized controlled study with cross-over design compared the effectiveness of precision ophthalmic tints in the prevention of headache in migraine sufferers. Seventeen patients chose the colour of light that optimally reduced perceptual distortion of text and maximized clarity and comfort. They were later given glasses with spectral filters providing optimal colour under conventional white lighting ('optimal' tint) or glasses that provided a slightly different colour ('control' tint). The tints were supplied in random order, each for 6 weeks, separated by an interval of at least 2 weeks with no tints. Headache diaries showed that the frequency of headaches was marginally lower when the 'optimal' tint was worn, compared with the 'control'. The trial extends to adults with migraine, the results of a previous double-masked study demonstrating, in children with reading difficulty, beneficial effects of precision tints in reducing symptom frequency. In the present study, however, the effects are suggestive rather than conclusive.

Optometrists frequently encounter patients with migraine and patients and practitioners sometimes suspect that visual stimuli or visual anomalies trigger headaches. There is a lack of evidence-based research on the issue, however. Some patients with migraine may be hypersensitive to visual stimuli, and it has been suggested that individually prescribed coloured filters might be an effective treatment to reduce symptoms from such stimuli. A recent randomised controlled trial showed such a treatment to be effective and the present paper reports on the optometric characteristics of the patients in this study. Twenty-one patients with neurologically diagnosed migraine were compared with 11 controls. No significant differences were found between the two groups with respect to refractive error, ocular pathology, colour vision, contrast sensitivity, accommodative function, strabismus and hyperphoria. The migraine group tended to be a little more exophoric, but by most criteria they were able to compensate for their exophoria as well as the control group. The migraine group were more prone to pattern glare than the controls (p = 0.004). The effects of precision tinted and control tinted lenses were investigated. The only variable to show a consistent and marked improvement with tinted lenses was pattern glare. The most likely mechanism for the benefit from individually prescribed coloured filters in migraine is the alleviation of cortical hyperexcitability (Wilkins et al. 1994) and associated pattern glare.

Visual correlates of specific learning difficulties (SpLD) include: binocular instability, low amplitude of accommodation, and Meares-Irlen Syndrome. Meares-Irlen Syndrome describes asthenopia and perceptual distortions which are alleviated by using individually prescribed coloured filters. Data from 323 consecutive patients seen over a 15 month period in an optometric clinic specialising in SpLD are reviewed. Visual symptoms and headaches were common. 48% of patients were given a conventional optometric intervention (spectacles, orthoptic exercises) and 50% were issued with coloured filters, usually for a trial period. 40% of those who were given orthoptic exercises were later issued with coloured overlays. 32% of those who were issued with coloured overlays were ultimately prescribed Precision Tinted lenses. Approximately half the sample were telephoned more than a year after the last clinical appointment. More than 70% of those who were prescribed Precision Tints were still wearing them daily, and results for this intervention compared favourably with data for non-tinted spectacles. The data suggest that many people with SpLD need optometric care and that the optometrist needs to be skilled in orthoptic techniques and cognisant of recent research on coloured filters.

Summary Visual correlates of specific learning difficulties (SpLD) include: binocular instability, low amplitude of accommodation, and Meares–Irlen Syndrome. Meares–Irlen Syndrome describes asthenopia and perceptual distortions which are alleviated by using individually prescribed coloured filters. Data from 323 consecutive patients seen over a 15 month period in an optometric clinic specialising in SpLD are reviewed. Visual symptoms and headaches were common. 48% of patients were given a conventional optometric intervention (spectacles, orthoptic exercises) and 50% were issued with coloured filters, usually for a trial period. 40% of those who were given orthoptic exercises were later issued with coloured overlays. 32% of those who were issued with coloured overlays were ultimately prescribed Precision Tinted lenses. Approximately half the sample were telephoned more than a year after the last clinical appointment. More than 70% of those who were prescribed Precision Tints were still wearing them daily, and results for this intervention compared favourably with data for non‐tinted spectacles. The data suggest that many people with SpLD need optometric care and that the optometrist needs to be skilled in orthoptic techniques and cognisant of recent research on coloured filters.