A case of amblyopia; electrophysiology and psychophysics of luminance and contrast.

Abstract

Amblyopia is a frequently occurring (3% of population) unilateral, visual defect. Even with present-day ophthalmological techniques no obvious cause for the reduced photopic visual acuity can be detected. Wald and Burian (1944) showed that amblyopia manifests itself in impaired form sense with behold of normal light sense. Miles (1949), Feinberg (1956) and Alpern et al., (1960) pointed out that the visual acuity function is more affected than the critical fusion frequency, which can be used as a criterion for luminance sensitivity. Since the spatial interaction of the amblyopic fovea seems to function as that of the retinal periphery of normal eyes [Grosvenor (1957); Flynn (1967); Meur et al., (1968)], Miller (1955) hypothesized that amblyopia is caused by a reduction of lateral inhibition between fovea) elements, resulting in a “physiological blurr”.