Monocular Fading and Feedback: Effects on Vision Changes in the Trained and Untrained Eye

Four subjects with a comparable degree of vision impairment in both eyes were trained, using a fading procedure, to increase the distance they could discriminate stimulus details in one eye. Subjects were provided training each day for a month, and discrimination testing was performed for each eye every other day. Changes in discrimination performance were analyzed according to a multiple baseline design across stimulus distances for the trained eye. Results suggested that changes in vision in the trained eye were related to implementation of the fading procedure across the testing distances. Correlations between discrimination changes in the trained and untrained eyes for the distances trained were uniformly high. This concurrent change in both eyes suggests that a central process responsible for regulating vision in both eyes, possibly accommodation, was being modified, rather than the fading technique operating only on the trained eye.