Visual Acuity, Contrast Sensitivity, Colour Vision: Thoughts on Psychophysical Exams in Neuro-ophthalmology

Abstract

Despite many technical advances, psychophysical testing of perceptual performance continues to play an important role in ophthalmic diagnostics, including neuro-ophthalmology. The present article considers methodological and clinical aspects of examining visual acuity, contrast sensitivity, and colour vision. In contrast to acuity, contrast sensitivity is at present rarely tested, despite often being a more sensitive marker of disease. In general, standardised procedures have the advantage of a high degree of comparability. However, tests that deviate from the standard might be better adapted to detect the characteristic impairments associated with a specific visual disorder, which justifies their application in certain cases. This also applies to colour vision testing. Preliminary evidence suggests that the measurement of colour saturation thresholds might be a more efficient and more sensitive alternative to conventional colour vision tests in cases of acquired colour vision deficiencies.