A review of the management of 323 consecutive patients seen in a specific learning difficulties clinic

Abstract

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.

Visual stress, its treatment with spectral filters, and its relationship to visually induced motion sickness

“…An overlay needs to be of a size sufficient to cover the text, but it does not have to cover the surround (Waldie and Wilkins, 2004). Individuals who find coloured overlays helpful usually prefer coloured lenses (Evans et al, 1999). The optimal colour for lenses is not the same as for overlays (Lightstone and Evans, 1995), and it can be selected with far greater precision.…”

“…Indications are that at least 1000 tints are needed to provide sufficient precision to increase reading speed optimally ). An audit of people using coloured lenses prescribed with the Intuitive Colorimeter system indicates that over 80% were still using them regularly at least a year after the last clinical contact (Evans et al, 1999, Maclachlan et al, 1993.…”

The Effect of Colored Overlays on Reading Fluency in Individuals with Dyslexia

“…This syndrome has been hypothesized as sensitivity to frequencies of the light spectrum that causes visual stress (Hoyt 1990). Colored overlays are claimed to alleviate visual stress and improve symptoms commonly related to dyslexia such as low reading rate, accuracy, and comprehension (Evans et al 1999;Rickelman & Henk, 1990; BWhat is Irlen Syndrome,n .d.). This claim may be because visual stress often co-occurs with dyslexia (Singleton and Trotter 2005;Singleton and Henderson 2007).…”

Using coloured filters to reduce the symptoms of visual stress in children with reading delay

“…It may be that some of these children have dyslexia but others may have different conditions (13). A large prevalence study of both selected and unselected samples would be useful to establish prevalence rates in the UK.…”

“…Beneficial effects were demonstrated through a range of outcomes: reductions in visual stress symptoms including eyestrain and headache (10); improved reading accuracy and comprehension (4); improved reading speed (11) and improved reading ability, motion sensitivity, convergence, and accommodation control (12). Sustained voluntary use of coloured filter lenses was found to be almost at the 80% level, demonstrating that the individuals experienced continued benefits (13,14).…”