Effects of three wavelength-cut lenses on visual function in the photopic and mesopic conditions

This study aimed to explore the impact of three wavelength-cut (TWC) lenses, which allowed 75% luminance transmittance while blocking wavelengths < 420 nm, approximately 460 nm, and approximately 585 nm, on visual function and color perception, and aging interaction effect. This single-center study enrolled 30 participants into two groups including 15 young participants (age 21.4 ± 1.3 years) and 15 older participants (age 71.7 ± 1.7 years). We used TWC lenses and a neutral density (ND) filter to assess the wavelength-cut effects on visual acuity, contrast sensitivity, and cone contrast sensitivity. Visual acuity and contrast sensitivity were assessed under photopic (luminance 85–100 cd/m²) and mesopic conditions (luminance 0.8 cd/m²). Significant interactions between age and lens conditions were observed for contrast sensitivity under photopic conditions (Bonferroni corrected α = 0.025, F_(1,28) = 7.98, P = 0.01, η² = 0.003), suggesting that contrast sensitivity to white and black gratings is better with TWC lenses (75%) than with the ND filter in young participants (F_(1,28) = 7.25, P = 0.01, η² = 0.206). However, the lens condition did not affect visual acuity and had only a minimal effect on cone contrast sensitivity for each cone type. In conclusion, TWC lenses, despite their nearly colorless and transparent appearance, can selectively block specific wavelengths to improve contrast sensitivity, while minimally affecting color perception. However, since the effect size of these interactions is very small, the impact is limited, therefore glasses should be prescribed with caution for young individuals.