Blue Light Exposure
Is It Really a Concern?
Quality sunglasses are designed to protect your eyes from harmful ultraviolet light rays emitted by the sun, since ultraviolet light can contribute to the development of eyelid cancers, cataracts, pinguecula and pterygia. But what about the blue wavelength of light? Blue light may cause oxidative damage to the eyes, and may play an integral role in causing age-related macular degeneration, which can lead to significant vision loss. Since you're protecting your eyes from the harmful effects of ultraviolet light, should you also be protecting them from blue light?
Basics of Blue Light
Your eyes are sensitive to a narrow band of frequencies referred to as the "visible light spectrum." Visible light—light capable of being seen by the human eye—consists of wavelengths of varying lengths. Blue light has a very short wavelength and is detectable by the human eye. Not only does it provide basic illumination to our world, blue light also helps to increase feelings of well being. But exposure to large amounts of blue light can be harmful to the eyes.
Sources of Blue Light
The plethora of electronic devices in use today, such as cell phones, tablets, and laptop computers, has drastically increased our exposure to blue light. Another source of blue light is energy efficient technology in the form of fluorescent light bulbs and LED lights. Research has determined that the lens inside the eye, and the pigment in the back of the eye, offer some protection against blue light. But this protective mechanism only lasts for a short period of exposure to the intense blue light, and during daylight hours.
Blue Light and Macular Degeneration
Perhaps the biggest threat of blue light is the role it plays in the development of age-related macular degeneration, mainly in the form of photo-oxidation. People with a higher risk for the disease should protect their eyes from blue light exposure. Some doctors recommend halogen lights as an alternative to other types of lighting.
Essilor, one of the foremost high quality lens manufacturers that we deal with, has developed a product to help protect us against blue light—not only outdoors, but also indoors. The new Anti-Reflective lens coating is called Prevencia, that filters blue light without impacting color perception. This may be a great option for people with macular degeneration or those at risk for developing the disease. It may also be important for people who've had cataract surgery, since intraocular lenses implanted during cataract surgery may not have as much protection against blue light.
Blue Light and Melatonin
Melatonin is a sleep hormone in our bodies that helps to regulate our circadian rhythms. Our eyes contain receptors that contain a photopigment called melanopsin that is sensitive to blue light. These cells give information to our body that regulates our sense of day and night. Blue light has been shown by researchers to actually boost attention and mood during the day, but chronic exposure to blue light at night can give messages to our brain to reduce melatonin secretion, which tells us to wake up and be more alert—potentially disrupting our circadian rhythm.
What You Should Know About Blue Light
Although blue light has been loosely linked to an increased risk of cancer, diabetes, heart disease, obesity, and disruptions in the circadian rhythm, it remains an important part of natural and artificial lighting. Ask Dr. Stone if you're at particular risk for eye conditions that may be associated with blue light exposure. This usually includes a review of your family history and a dilated retinal eye exam.
As always, keep the following tips in mind for UV eye protection:
· Limit extended sun exposure whenever possible.
· Wear wide-brimmed hats while in the sun.
· Consider a melanin pigmented polarized lens. Although it may cause changes in color perception, it cuts down outdoor blue light exposure.
· Reduce blue light exposure by keeping digital devices out of the bedroom.
· Reduce internet browsing in the evening to reduce potential blue light from your computer screen and potential changes in circadian rhythm.