Blue light (High-energy visible light) (HEV)

Blue light, or high-energy visible (HEV) light, refers to the 400-500 nm wavelength range of the visible spectrum that reaches the macular and retinal tissues [1]. It is not a biological molecule or receptor but a physical stimulus that interacts with various retinal chromophores, most notably melanopsin (OPN4) for circadian regulation and A2E (a component of lipofuscin) for photochemical reactions [2, 3]. While blue light is essential for non-image-forming visual functions and color vision, chronic or intense exposure is associated with the generation of reactive oxygen species (ROS) and oxidative stress in the retinal pigment epithelium (RPE) and photoreceptors [1, 4]. This phototoxicity is a significant contributing factor to the pathogenesis and progression of age-related macular degeneration (AMD) [4]. Therapeutic strategies do not target blue light in the traditional pharmacological sense; instead, they involve the use of macular pigments such as lutein and zeaxanthin, which act as internal filters to absorb blue light and as antioxidants to mitigate oxidative damage [5]. Additionally, visual cycle modulators like emixustat are being investigated to reduce the accumulation of blue light-sensitive chromophores like A2E to prevent retinal phototoxicity [6]. References: [1] Hunter et al., Prog Retin Eye Res, 2012; [2] UniProt, Q9UHM6; [3] Sparrow et al., J Biol Chem, 2000; [4] Ratnayake et al., Sci Rep, 2018; [5] NIH ODS, Lutein/Zeaxanthin; [6] Kubota et al., Retina, 2014.

Other names

HEV lightShort-wavelength visible light400-500 nm radiationBlue-violet light

Absorption and filtration of high-energy visible light by macular pigments; neutralization of reactive oxygen species; reduction of blue light-absorbing chromophore accumulation.