High-energy visible light is a frequently overlooked component of solar radiation that presents a potential hazard to long-term ocular health. As is the case with UVR, increasing educational efforts to recognize the risk and understand how to best protect the eyes from it are crucial to protecting and preserving Healthy Sight.
Sources of Blue Light
The visible spectrum includes wavelengths of 700 nm to 400 nm; blue light is found at the lower end of the spectrum (400 nm to 500 nm). While solar radiation is the most common and widespread source of blue light, as in the case of UVR, there are many artificial light sources that emit blue light as well, including arc welding equipment and lasers.
Chronic Exposure to Blue Light and Healthy Sight
The Chesapeake Bay Watermen Study is an important source of epidemiologic data on the possible correlation between exposure to sunlight and long-term ocular health. The full spectrum of visible light--including visible blue (400 nm to 500 nm) and visible deep blue (400 nm to 450 nm) light—were considered.
The clinical effects of exposure were determined by obtaining detailed exposure histories, clinical examinations, and retinal photographs from 838 Chesapeake Bay watermen who, due to the outdoor nature of their work and the reflective properties of the water, generally would be expected to have a greater than average lifetime exposure to solar radiation.
The authors reported a higher prevalence of pterygium and climatic droplet keratopathy in people with histories of higher exposure to blue or visible light. This same group also had a higher prevalence of advanced age-related macular degeneration (AMD).