Changes in contrast sensitivity during the first six months of soft lens wear.

Changes in the contrast sensitivity function (CSF) and corneal thickness of six subjects were monitored during the first 6 months of soft lens wear. Contrast sensitivity suffered a temporary reduction during the first two weeks of wear, subsequently recovering rapidly to normal baseline levels. Corneal thickness increased by 4.9% on the first day of wear, thereafter gradually returning to, but never attaining, prefitting levels. No evidence was found to support complaints of poor vision by long-term soft lens patients. The etiology of the contrast decrements revealed in the early (or adaptation) stages of soft lens wear is discussed.