Avoiding the blues

| By: Susie Clark | Posted in:

Protecting Eyes from High-Energy Visible Light

Think ultraviolet (UV) radiation is the only risk to the eyes from sunlight? Think again. Research suggests that, like UV, the sun’s high-energy visible radiation — called HEV or “blue” light — also can cause damage to the eye and surrounding tissues. HEV radiation is called “blue light” because it comprises the higher-energy portion of the visible light spectrum, which, if isolated from the entire sunlight spectrum, is violet or blue in color. The shorter the wavelength of light, the higher the energy of those rays — and the more potential damage they can do to the eye.

Light Spectrum
UV radiation has wavelengths ranging from 100 nanometers (nm) to about 400 nm. Visible light ranges from approximately 400 to 700 nm; and the HEV or “blue light” portion of the visible light spectrum ranges from about 400 to 500 nm.

Potential Harm From Blue Light

Research has shown that prolonged exposure to high-energy visible light can cause at least two specific eye problems:

Damage to the Retina

Exposure to blue light has been associated with damage to retinal cells and tissues that
may increase the risk of age-related macular degeneration (AMD). In particular, a large European study published in Archives of Ophthalmology (now JAMA Ophthalmology) in 2008 found that HEV radiation exposure – when combined with low blood plasma levels of vitamin C and other antioxidants – was associated with the development of  macular degeneration in older adults. The study authors concluded their results “suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients” to reduce the risk of eye damage from blue light.

Premature aging of the skin

Like UV, blue light also has been implicated in premature aging of the skin that can result  in loss of elasticity, wrinkles and possibly a higher risk of skin cancer around the eyes. Researchers believe HEV light induces inflammation and an increase in free radicals that deplete antioxidants normally present in the skin. This in turn reduces the skin’s normal healing ability, leading to premature aging. Studies also have found that exposure to HEV light changes the expression of genes in the skin that control pigmentation, causing changes that may increase the risk of skin cancer.

Preventing Eye and Skin Damage From Blue Light

The best way to protect your patients’ eyes from the potentially harmful effects of blue light is to prescribe sunglasses that absorb a significant portion of HEV rays, especially those with the shortest wavelengths. Unlike UV radiation, some blue light actually has a beneficial effect in the eye. It appears that a certain amount of HEV rays reaching the retina is helpful in maintaining the body’s circadian rhythms that are important in maintaining a healthy daily sleep pattern. Therefore, though blocking a significant percentage of blue light is advised to prevent eye damage, it’s not essential (or even advisable) that sunglasses absorb all blue light. Also, allowing some longer-wavelength blue light through the lenses is helpful in maintaining good color perception when wearing sunglasses.

Give your patients the best protection under the sun with Coppertone Polarized Lenses. With 2x the solar blue light protection  and 100% UVA/UVB protection, Coppertone Polarized Lenses offer a level of health protection that competitors can’t match.

Reducing Blue Light Also Sharpens Vision

In addition to protecting your eyes from harmful radiation, wearing sunglasses that absorb a significant amount of HEV light also sharpens your eyesight. This is because visible light with shorter
wavelengths scatters more easily, creating a haziness that reduces contrast and clarity. Sunglasses that more effectively reduce certain HEV wavelengths increase the sharpness of vision in bright sunlight, compared with sunglasses that absorb less blue light.

To best protect eye health and provide the sharpest vision outdoors, prescribe quality sunglasses that block 100 percent UV and the appropriate amount of HEV rays for optimum visual performance without affecting circadian rhythms.