The present method describes a new method for the measurement of dark adaptation. The dark adaptation status of subjects may then be used to identify those subjects who are at risk of developing and/or who are currently suffering from a variety of disease states having their clinical manifestations in impaired dark adaptation. The disease states include, but are not limited to, age related macular degeneration, vitamin A deficiency, Sorsby's Fundus Dystrophy, late autosomal dominant retinal degeneration, retinal impairment related to diabetes and diabetic retinopathy. An apparatus for administering the test method described is also provided. The method is performed as follows: After bleaching the eye to be examined, light stimuli of variable intensity are provided to the eye of the subject. Based on feedback from the subject, the adaptation threshold is determined as a function of time. The data collected may be subject to a noise reduction protocol.