Improvement of visual acuity in partially and fully sighted subjects as a function of practice, feedback, and instructional techniques.

Three experiments were conducted to examine improvement of partially (20/200 or 6/60) and normally (20/20 or 6/6) sighted adults. Measures of resolution and vernier acuity were examined in the first two experiments to determine whether practice, feedback, and instructions would have differential effects on the degree of visual improvement achieved in a 20-min. testing session. The results indicated extensive visual work to be the important factor in the improvement of impaired vision. The third experiment compared monocular and binocular depth perception of individuals with unilateral optic atrophy. The results yielded an unexpected finding where binocular depth perception was, in most cases, inferior to that of the strong eye alone. The first two experiments demonstrated the possibility of improving impaired visual functions and the third experiment suggests important implications for a theoretical model of depth perception with limited vision.