Like ultraviolet (UV) radiation, visible blue light, also known as High-Energy Visible or HEV, has both benefits and dangers. Blue light is the portion of the visible light spectrum with the shortest wavelengths and highest energy. It’s important to reduce exposure to blue light because it penetrates all the way to the retina (the inner lining of the back of the eye). Too much exposure to blue light can damage light-sensitive cells in the retina, increase eye strain and/or may lead to macular degeneration.
An easy solution is to wear glasses with technology that absorbs blue light and helps reduce glare. Most glasses start around $10 – so there is a pair for any budget. If worn regularly, these glasses will likely reduce the risks mentioned above.
Here are important things you should know about blue light or HEV:
1. Blue light is everywhere.
Sunlight is the main source of blue light. But there are also many man-made indoor sources of blue light that emit significant amounts, including fluorescent and LED lighting and devices such as smartphones, tablets, laptops, and flat screen televisions. Most of us are working in the field with exposure from the sun, on the floor with exposure from harsh lights and screens, or a combo of both. The amount of blue light exposure from the sun and electronic devices has many eye doctors and other health care professionals concerned about possible long-term effects of blue light on eye health.
2. The eye is not very good at blocking blue light.
Anterior structures of the adult human eye (the cornea and lens) are very effective at blocking UV rays from reaching the light-sensitive retina at the back of the eyeball. In fact, less than 1% of UV radiation from the sun reaches the retina, even if you aren't wearing sunglasses. But blue light is another story. Virtually all visible blue light passes through the cornea and lens and reaches the retina. In a future post, we’ll dive deeper into the differences between lens colors and which is best for you. For now, when it comes to reducing blue light, we’ll look at yellow, amber, orange, and blue lenses.
Yellow-tinted, amber-tinted, orange-tinted Lenses: (76-86% VLT*) Enhance contrast in low light conditions, brighten environments, and block blue light. Applications: shooting, cycling, and indoor working or playing conditions.
Blue-tinted Lenses: (68-78% VLT) Reduce yellow light, perform in both indoor and outdoor environments. Applications: working conditions with sodium vapor lighting and excessive glare.
*visible light transmission (VLT)
3. Blue light contributes to digital eye strain.
High energy blue light has short wavelengths and scatters more easily than other visible light so we have trouble focusing on it. So, when you're in the sun for extended periods of time and/or looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused “visual noise” reduces contrast and can contribute to digital eye strain. It may lead to eye problems over time. Research has shown that contrast is significantly increased with lenses that block blue light.
Whether you are working inside on your devices, outside with greater sun exposure, or a combo of both, it is worth investing in specialty glasses that help block out blue light and reduce glare. At the end of the day, your eyes (and body) will thank you. With reduced eye strain you may feel less tired and may have reduced headaches and overall aches and pains.