Ultraviolet and Blue light ultraviolet light is the part of the spectrum of invisible light below 286nm to 400nm. This portion of the spectrum is harmful to the eye and can lead to cataracts and other diseases of the eye such as age-related macular degeneration. Damage to the retina is the most hazardous concern from light. Retinal damage can be structural, photochemical, and thermal, which can vary depending on the power level, wavelength, and exposure time.
Sources of Ultraviolet Light
The sun is considered the main source of ultraviolet light, but there are other sources such as welder’s flash, fluorescent lighting, video display terminals, xenon arc lamps, and high intensity mercury vapor lamps.
UV Light Types
UV light is distributed into three segments, namely A, B, and C. UVC is the least harmful and UVA the most harmful to the eye.
- UVC (below 286nm) is filtered by the earth’s ozone layer.
- UVB (286-320nm) is absorbed by the cornea and also causes sunburn and snow blindness.
- UVA (320-400nm) is the type of UV radiation that is most damaging and is transmitted to the lens of the eye.
Melanin is the part of the skin, hair, and eyes that absorb damaging UV light and blue light. Melanin is considered a natural sunscreen protection. The higher the amount of melanin we have, the higher the protection we have against damaging light rays. As we age, we lose melanin, and by age 65, almost all melanin protection is gone increasing our risk of developing eye diseases such as macular degeneration.
According to the Schepens Eye Institute, blue rays from the spectrum may speed up development of AMD compared to the other rays in the spectrum. Bright lights like the sunlight or its reflection in bodies of water or the desert can make macular degeneration worse. The use of sunglasses is recommended to protect your eyes from blue/violet and UV light to prevent macular degeneration.
Who should get UV light protection?
People who work in the sun or are always exposed to the sun, such as construction workers, police officers, farmers, lifeguards, beach goers, etc. should get ultraviolet light protection.
Additionally, people who are taking medications, particularly photosensitizing drugs such as anti-hypertensive medications, antibiotics, diuretics, tranquilizers, oral contraceptives, and artificial sweeteners.
UV Protection Eyewear Guide
To protect your eyes from the harmful UV rays, sunglasses or eyeglasses with UV protection are recommended. UV light is harmful in both sunny and overcast days. Sunglasses should protect from UV radiation up to 400 nanometers, extending to the part of the spectrum to make sure that ultraviolet light is blocked. Sunglasses must have a label of UV 400 to ensure ultraviolet light protection.
Consult with your eyecare professional to make sure your eyewear includes UV light protection to protect your eyes from UV radiation damage.
According to scientific evidence, blue light is a risk factor for developing macular degeneration as well as other eye diseases such as cataracts. Blue light from the sun and blue light from electronic devices are different. Although studies have shown that blue light can damage your eyes, it was only evident when the light energy was 3 microwatts or greater. Electronic devices typically emit no greater than 1 microwatt.
According to a study in 2017 by the Department of Optometry and Vision Sciences of The University of Melbourne, Australia, and the Centre for Applied Vision Research of London, blue light blocking glasses did not show any evidence of providing any protection against macular damage, eye fatigue, or sleep quality.
Although it is important to wear UV protective sunglasses while exposed to the sun, there is limited evidence to support the use of blue light blocking lenses for electronic devices. Additionally, there is limited evidence to suggest that the level of blue light exposure from electronic devices can damage the eyes or that any current blue light blocking glasses provide any significant protection. It is best to always consult with your eye-care provider to see what’s right for you.
To learn more about blue light, click HERE.
Adapted from macular.org