James P. Comerford

High myopia does not affect contrast sensitivity

The axial elongation of high myopia is known to induce tangential stretching forces on the retina. Such forces might be expected to compromise retinal circuitry and thus affect the temporal and spatial contrast sensitivity function. In fact, we find that simple high myopes have normal contrast sensitivity for stationary gratings, moving gratings, and uniform field flicker. This suggests that, unlike many other retinal disease processes, the high myopes retina retains its normal integrity until the outer retina is compromised.

Use of various measures of visual acuity and contrast sensitivity in the evaluation of monocular occlusion and active vision training of three adult amblyopes.

ABSTRACT Three adult amblyopic patients who underwent vision training involving monocular occlusion of the nonamblyopic eye and stimulation of the amblyopic eye using simple fixation exercises and a spinning grating procedure were evaluated using five different types of acuity testing and two methods of contrast sensitivity. It was found that contrast sensitivity and isolated Landolt C acuity improved sooner and to a greater extent than the more complex visual acuity tasks. One patient who improved only on the simpler tasks complained that the enhanced contrast due to training made vision in that eye less acceptable because it was more confusing. The results show that multiple measures of visual acuity and contrast sensitivity are necessary to adequately monitor the effects of occlusion therapy.

The Effect of Age on the Westheimer Function

The Westheimer function is relatively stable in healthy observers between 20 and 70 years of age. The sensitization portion of the function is unaffected by age and only in the oldest observers does a small but significant decrease in desensitization occur.