Effect of hydrogel lens wear on contrast sensitivity.

Conflicting reports on the adequacy of the visual performance provided by hydrogel contact lenses continue to appear in the literature. We conducted a study to determine the effect on visual performance, as assessed by contrast sensitivity measurements, of (1) lens wear of optimally fitting 38% water content lenses and (2) altered lens parameters, including fitting characteristics, of 38% and 67% water content lenses. During normal wear of lenses, neither the lenses themselves nor any contact lens-induced corneal changes produced measurable visual losses. The visual performance was also independent of lens fit or lens thickness over the ranges used here. The higher water content lenses provided marginally poorer visual performance.