Efficacy of Coloured Overlays and Lenses for Adults With Reading Difficulty

Participants will be adults aged from 8 years, with symptoms of visual stress (discomfort when reading or experiencing perceptual symptoms when reading such as letters moving or distorted) or with a diagnosed reading difficulty (dyslexia). Participants will be recruited from the City University London optometry clinic and the City University London Learning Success unit. Participants within this age range and with visual stress will be eligible to participate. Potential participants with an ocular or systemic condition with possible impact on vision (e.g. amblyopia or diabetes respectively) or with intellectual disability will be excluded from the study. Each potential participant will undergo an eye examination prior to participation, during which the following tests will be conducted:

Prior to study entry:

History and symptoms Direct ophthalmoscopy (to check for ocular abnormality) Retinoscopy and subjective refraction (to quantify corrected and uncorrected refractive error) Cover tests (to look for any eye misalignment)

Baseline tests on study entry:

Each eligible participant who agrees to take part in the study will undergo testing with coloured overlays, to determine whether a particular overlay appears to be beneficial in terms of reducing difficulty or discomfort while reading. If so, the participant will be provided with the overlay to use for a period of two weeks, to determine whether it is consistently beneficial when reading during that period. In addition, the Wilkins Rate of Reading Test (WRRT) will be carried out at this baseline stage with and without the overlay.