Effects of Three-Wavelength-Cut Lens on Cone Contrast Sensitivity.

The purpose of this study was to quantitatively evaluate the effects of a three-wavelength-cut (TWC) lens, a type of wavelength-control lens, on cone contrast sensitivity in healthy adults using ColorDx CCT-HD (KONAN MEDICAL, Inc.). TWC lenses selectively attenuate light at wavelengths below approximately 420 nm, as well as around 460 and 585 nm. Fifteen healthy adults (mean age, 39.7 ± 9.0 years) were examined under two conditions: full refractive correction alone and full refractive correction with the TWC lens. Cone contrast sensitivity scores corresponding to long-wavelength-sensitive cones (L-cones), middle-wavelength-sensitive cones (M-cones), and short-wavelength-sensitive cones (S-cones) were measured. The L-cone-axis score was treated as the primary outcome, with the M- and S-cone-axis analyses considered exploratory. Paired comparisons were supplemented with a two-way repeated-measures ANOVA using lens condition and cone axis as within-subject factors. The primary L-cone analysis showed a significantly higher contrast sensitivity score with the TWC lens than without it (p = 0.022). The repeated-measures ANOVA showed a significant main effect of lens condition (p = 0.024), but no lens condition × cone axis interaction (p = 0.858). These preliminary findings suggest an overall lens-associated change in cone-axis-specific contrast sensitivity, while providing no statistical evidence that the effect is selective to the L-cone axis.