Visual Acuity in Contact Lens Wearers

Purpose. The difference between high‐ and low‐contrast visual acuity provides a sensitive indicator of vision loss in ocular disease; however, the effect of refractive error correction on this difference is still debated. Methods. High‐ and low‐contrast visual acuity was measured in 116 rigid gas permeable contact lens wearers, 51 spectacle wearers, and 50 soft contact lens wearers with habitual and best correction. Twenty‐nine of the soft contact lens wearers reported that they wore disposable contact lenses (discarded on a monthly or more frequent basis), whereas the other 21 soft contact lens wearers wore traditional soft contact lenses. Results. Rigid gas permeable contact lens wearers had statistically worse high‐contrast habitual visual acuity than spectacle wearers (Tukey‐Kramer, p = 0.0075). Traditional soft contact lens wearers had significantly worse low‐contrast visual acuity compared with all other groups (Tukey‐Kramer, p < 0.02 for each comparison). Traditional soft contact lens wearers had a significantly larger difference between high‐ and low‐contrast visual acuity with best correction compared with rigid gas permeable wearers (Tukey‐Kramer, p = 0.0099). Conclusions. Rigid gas permeable contact lens wearers had statistically worse habitual high‐contrast visual acuity compared with spectacle wearers, but no difference was present under best‐corrected conditions. We hypothesize that rigid gas permeable contact lens wearers were not wearing their optimal correction habitually. Traditional soft contact lens wearers had significantly worse low‐contrast visual acuity. They also had a larger difference between their best‐corrected high‐ and low‐contrast visual acuity scores compared with rigid gas permeable contact lens wearers.