Evaluation of colour vision, mesopic vision, visual evoked potentials and lightness discrimination in adult amblyopes.

This is a study conducted on thirty adult strabismic and anisometropic amblyopes using colour vision tests, the lightness discrimination test, mesopic vision and visual evoked responses, in order to determine the probable site of the amblyopic defect. The results showed that, in its progressed stages, amblyopia is associated with eccentric fixation, abnormal hue discrimination, disturbed lightness discrimination and mesopic vision, and attenuation of the amplitude of the pattern visual evoked response. It is suggested that these abnormalities result from a defect involving the extrastriate higher visual association areas 18 & 19 of Brodmann.