Measurements were made of the contrast required to see the direction of motion of drifting gratings (Part 1) and of moving bars (Part 2). The spatial frequency at which least contrast is required to see sinusoidal gratings decreases as their velocity increases, but peak sensitivity is identical at all velocities up to 800 deg/sec. Similarly, the wider a single bar, the higher the velocity at wh...

A natural auditory scene often contains sound moving at varying velocities. Using a velocity contrast paradigm, we compared sensitivity to velocity changes between continuous and discontinuous trajectories. Subjects compared the velocities of two stimulus intervals that moved along a single trajectory, with and without a 1 second inter stimulus interval (ISI). We found thresholds were threefold...

Contrast sensitivity functions were measured for sinusoidal gratings from a sample of 10 anisometropic amblyopes. A high spatial frequency deficit was found from tests of the amblyopic eyes of all subjects. This defect decreased with spatial frequency and was correlated with the magnitude of anisometropia. Controls were instituted to rule out psychophysical method and residual defocus as possib...

Arden gratings were used to measure contrast sensitivity in 40 patients with retinitis pigmentosa whose Snellen visual acuity was 6/12 or better. When compared with a group of 30 normal subjects the patients with retinitis pigmentosa had substantially decreased contrast sensitivity, especially at high frequencies. The Arden grating test appeared to be a sensitive test of abnormal central visual...

purpose: to compare tecnis z9000 and akreos ao aspheric intraocular lenses (iols) in terms of spherical aberration and contrast sensitivity. methods: thirty-four eyes of 34 patients undergoing phacoemulsification cataract surgery were randomly assigned for implantation of tecnis or akreos ao iols. three months postoperatively, best-corrected visual acuity (bcva), spherical aberration (with 4 an...