Visual performance with tinted contact lenses

During extensive research of the several tinted contact lenses on the market, a lack of information was noted as to whether or not tinted contact lenses can effect visual acuity under conditions of varying contrast. With this in mind we conducted a study to determine the effect of tinted contact lenses on visual performance under high and low contrast conditions. Using twenty-four research subjects, high and low contrast visual acuities were documented in order to compare performance with tinted to clear contact lenses. Two tints were chosen, royal blue and evergreen, with each person serving as their own control by wearing a pair of clear lenses. Subjects accepted for the study were required to have small refractive errors, + 1.00 to -4.00 diopters with astigmatism less than 0.75 diopters. Acuities were measured using Bailey-Lovie LogMAR contrast acuity charts, and the data analyzed with paired t-tests. The data showed that visual acuity decreased by approximately 1/2 a Snellen line under high and low contrast conditions compared to the clear lens performance. These data suggest that visual performance deficits can occur when tinted lenses are prescribed for cosmetic purposes, particularly under conditions of varying contrast. This may have impact in situations ranging from safety in the workplace to performance in sports or fine visual motor tasks, and it is suggested that patients be informed of possible difficulties when wearing deeply tinted cosmetic lenses