Low-contrast visual acuity measurements in single-vision and bifocal soft lens wearers

Background. We sought to consider the low success rate of bifocal soft contact lenses through low-contrast visual acuity measurements using one popular design.

Methods. Visual performance was measured in 23 nonpresbyopic patients with a single-vision and a concentric bifocal soft contact lens.

Results. There was a statistically significant difference (p = 0.01) between the performances of the two soft lenses when measuring low-contrast visual acuity using a Bailey-Lovie chart. However, no significant difference was found when measuring high-contrast Snellen visual acuity.

Conclusion. While Snellen acuity is the most widely accepted form of acuity measurement, low-contrast visual acuity may be a sensitive measure of visual function when evaluating bifocal soft contact lenses.