The training of visual acuity in myopia.

Seventeen myopes were trained with a computerized optometer to increase their far-point visual acuity from up to 20/800 to 20/25 for limited durations under conditions where "squinting" and pupil size were controlled. No associated changes in refraction were found. The results are best explained by the formation of an artificial contact lens resulting from tear-film changes. Measuring contrast sensitivity across a range of spatial frequencies is suggested to investigate the possibility that a learned perceptual process may also be involved.