Modelling the effect of commercially available blue‐blocking lenses on visual and non‐visual functions

Abstract

Background

Blue‐blocking lenses (BBLs) are marketed as providing retinal protection from acute and cumulative exposure to blue light over time. 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. This study measured the spectral transmittance of BBLs and evaluated their effect on blue perception, scotopic vision, circadian rhythm, and protection from photochemical retinal damage.

Methods

Seven different types of BBLs from six manufacturers and untinted control lenses with three different powers (+2.00 D, −2.00 D and Plano) were evaluated. The whiteness index of BBLs used in this study was calculated using Commission International de l'Eclairage (CIE) Standard Illuminates D65, and CIE 1964 Standard with a 2° Observer. The protective qualities of BBLs and their effect on blue perception, scotopic vision, and circadian rhythm were evaluated based on their spectral transmittance, which was measured with a Cary 5,000 UV–Vis–NIR spectrophotometer.

Results

BBLs were found to reduce blue light (400–500-nm) by 6–43 per cent, providing significant protection from photochemical retinal damage compared to control lenses (p ≤ 0.05). All BBLs were capable of reducing the perception of blue colours, scotopic sensitivities and circadian sensitivities by 5–36 per cent, 5–24 per cent, and 4–27 per cent, respectively depending on the brand and power of the lens.

Conclusion

BBLs can provide some protection to the human eye from photochemical retinal damage by reducing a portion of blue light that may affect visual and non‐visual performances, such as those critical to scotopic vision, blue perception, and circadian rhythm.

Key words:

• blue‐blocking lenses
• non‐visual functions
• transmittance
• visual functions

ACKNOWLEDGEMENTS

The authors of this study wish to thank Mr Justin Baker (JuzVision), Mr Tim Thurn (Essilor Australia) and Ms Dubravka Huber (Optometry Clinic, School of Optometry and Vision Science, UNSW Sydney) for providing BBLs used in this study. We thank Dr Kathleen Watt for valuable discussion.