Visual performance measured under simulated atmospheric blue haze conditions is improved through the addition of a HEV-filtering additive to soft contact lenses

Blue haze (BH) is a significant factor that limits visual range outdoors by reducing the contrast of distant objects. This study evaluated how varying the intensity of veiling light, filtered to approximate the blue haze spectrum, affected visual performance in participants wearing either clear or high energy visible (HEV)-filtering contact lenses. A total of 121 participants (mean age 33.8 ± 13.6 years) were tested using a stratified, controlled, prospective, double-masked, randomized, bilateral crossover design. Participants completed two visits, each time wearing either HEV-filtering or clear lenses on both eyes, with lens type counterbalanced across visits. Three lens designs were evaluated: spherical (n = 41), multifocal (n = 40), and toric (n = 40). Visual performance was measured with a custom optical apparatus that measured peak contrast sensitivity with an ancillary xenon light channel filtered to mimic blue haze. The intensity of veiling light required to obscure a grating target served as the primary outcome, expressed as log relative energy (LRE). Across all lens types, participants could tolerate significantly more veiling light when wearing HEV-filtering lenses compared to clear controls. LRE differences were 0.22 for spherical, 0.16 for multifocal, and 0.21 for toric lenses, corresponding to performance improvements of 6.9%, 5.3%, and 6.6%, respectively. These findings suggest that incorporating HEV-filtering technology into soft contact lenses can meaningfully enhance visual performance under conditions of atmospheric blue haze, with improvements aligning with the optical density of the HEV filter (∼0.22).