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). The objective outcome showed no statistically significant difference between the spherical or aspheric design lenses for high- or low-contrast visual acuity. However, based on subjective outcomes, this study implies a 2:1 preference for the aspheric design lens, suggesting the consideration of individual corneal topography and the importance of diagnostic lens fitting for patient satisfaction.