Abstract
Purpose :
Recent studies investigated whether blue-light filters contribute to reduction of digital eye strain, with mixed results. Nonetheless, The Vision Council reports that 60% of those not using blue-filtering lenses are interested in the technology. One manufacturer makes contact lenses (CL) that filter 60% of blue-violet light. How this CL affects color vision assessment is unknown. Since color vision is important for many vocations and avocations, we compared achromatic contrast sensitivity, AC, and blue color contrast sensitivity, BC, assessed by cone-isolation, (ColorDx, Konan Medical) between a blue-filtering CL (BF) and a CL with a “visibility” tint (VT).
Methods :
AC (Gabor patch: 1.22, 0.4, 0.1 cpd and high contrast resolution acuity) and BC (Landolt C) were assessed in randomized order in a randomized eye of 51 healthy adults (aged 21-27 years) without ocular surface disease, with 20/20 vision at near, and with less than 1 diopter of cylinder correction. Testing conditions were: room illumination low, non-tested eye patched, test distance 50 cm, stimulus duration up to 5 seconds, stimulus presentation via a 4-alternative forced choice procedure. The psi-marginal adaptive method (instrument standard) was used to determine threshold. Two blocks of trials were administered per condition, 1 each with BF and VT, in random order, with a rest break of 2-3 minutes between blocks. CL power was the same for both CLs per subject and within +0.50 diopter of subject’s spherical equivalent refraction.
Results :
Related-samples Wilcoxon signed rank test indicates no difference in distribution of AC values for the 2 CL conditions for any of 3 spatial frequencies tested (P > .05); paired samples t-test indicates achromatic resolution acuity is significantly better for BF condition (mean difference LogMAR = .046 ± .094, 2-tailed P = .001, 95% CI [.020, .073]). Paired-samples t-test indicates no difference in mean BC between CL conditions (mean difference log BC = -.025 ± .144, 2-tailed P = .22, 95% CI [-.066, .015]). No differences in performance occurred based on temporal order of testing or CL condition.
Conclusions :
In these young adults, only high contrast achromatic resolution acuity was significantly different with BF compared to VT. BC was not different for the 2 CLs. Whether other tests of blue color perception are differently affected by filters in commercially available CLs remains to be explored.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.