High- and low-contrast visual acuity measurements in spherical and aspheric soft contact lens wearers.

Visual reduction produced by spherical aberration is not always apparent with high-contrast optotypes, therefore, a measure of low-contrast visual acuity (LCVA) may be more revealing. In theory, by applying a series of curves to produce an aspheric surface, one should be able to reduce the defocus resulting from spherical aberration. This clinical investigation sought to evaluate high- and low-contrast visual acuity under natural conditions using the CooperVision Frequency 55 spherical and aspheric planned replacement soft contact lenses (CLs).