Abstract
Purpose :
Blue-Blocking Lenses (BBLs) are marketed as providing retinal protection against hazardous blue light, which has been claimed to be linked to age related macular degeneration. Additionally, the selective reduction in visible wavelengths transmitted through BBLs is known to influence the photosensitivity of retinal photoreceptors, which affects both visual and non-visual functions. The aim of the present study is to investigate the protective effect of BBLs and their effect on blue light perception, scotopic vision, and non-visual performance.
Methods :
We measured the spectral transmittances of five types of BBLs (Crizal Prevencia, SeeCoat Blue, JuzVision, Blu-OLP, Blue Guardian) with three different powers (2D, –2D and no power) and one untinted lens as a control lens using a Cary 5000 UV-Vis-NIR spectrophotometer with an integrated sphere. The measurement of transmission spectrum was performed at 5 nm intervals at a speed of 120 mm/seconds from 280 to 780 nm at a bandwidth of 2 nm. The BBLs effect on phototoxicity, scotopic vision, blue perception and non-visual physiologic responses were assessed using their spectral transmittances. The whiteness index (WI) of BBLs used in this study was calculated using CIE Standard Illuminates D65, and CIE 1964 Standard with a 2° Observer.
Results :
The BBLs were found to reduce the blue light hazard between 380 nm to 550 nm by 12–40% depending on the brand and the power of the lens. All the tested BBLs transmit (i) (73– 97%) blue light at 480 nm responsible for activating the melanopsin in retinal ganglion cells to control non-visual physiologic responses in the human body (ii) (77– 95%) of blue light at 507 nm responsible for the activation of rod photoreceptors and important for scotopic vision (iii) (70 – 88%) of blue light at 430 nm responsible for activating S-cone photoreceptors and enhancing blue perception. In regards to the WI of the BBLs, the lightness of each lens was measured relative to a preferred white. The results showed a variation in the WI values among BBLs with and without powers that had the same brand name.
Conclusions :
Our study showed that the commercially available BBLs with and without powers could effectively protect the retinae by attenuating the most harmful blue wavelength while allowing a portion of blue light wavelengths that are required for scotopic vision, blue perception, and non-visual functions.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.