Seeing through the veil: blue-light filtering and peak contrast sensitivity in pseudophakic patients.

PURPOSE: Atmospheric short-wave scattered light (blue haze) limits visual range by reducing the contrast of distant objects. While theoretical models and prior research suggest that filtering short wavelengths can improve visual range, significant individual differences persist in tolerance to veiling luminance, even among individuals with similar ocular health and acuity. This study examined whether a commercially available blue-light filtering (BLF) lens design could enhance visual range under simulated blue haze conditions in an older pseudophakic population.

METHODS

Forty older pseudophakic adults (M = 71.15 ± 5.82 years) were tested using a randomized, controlled, cross-over design. Visual range was assessed via a custom two-channel optical system presenting a sinusoidal grating target veiled by adjustable blue haze (Correlated Color Temperature = 9424 K). Participants viewed the target through a clear control lens and a test BLF lens in randomized order. Visual range thresholds, defined as the maximum blue haze energy tolerated before target detection failed, were determined using the psychophysical method of limits.

RESULTS

Participants tolerated significantly greater (U = 1035.00; p = 0.024) average blue haze energy with the BLF lens (3.49 log relative energy [LRE]) than with the clear control lens (3.43 LRE). On average, the BLF lens allowed participants to withstand approximately 19% more veiling luminance before target obscuration.

CONCLUSIONS

Consistent with theoretical predictions and prior findings in younger adults, BLF lens designs significantly enhanced visual range in older pseudophakic participants under simulated blue haze conditions. These findings suggest that BLF lenses may offer functional visual benefits in older adults, especially in populations with intraocular lens implants lacking native blue-light filtration. Future research should extend these results using field studies in outdoor environments.