Blue Light: Protecting Your Eyes
Blue light by definition is the visible light ranging from 380 to 500 nanometers (nm). Visible light, a form of electromagnetic radiation, refers to the spectrum of light or wavelengths that are visible to the human eye. This range is generally from 390 to 700 nm. The prismatic spectrum of light perceivable by the human eye is also known as “white light” or sunlight.
Sunlight contains color light rays, and their range of shades.
Blue light, also broken down into blue-violet and blue-turquoise light, has the shortest wavelengths and the highest energy, followed by green, yellow, orange and red, which has the longest, lower energy wavelengths. Blue light, also known as high energy light makes up about one-third of all visible light. The blue-violet light rays also sit directly next to the UVA rays on the light spectrum.
Exposure to Blue Light
The main source of blue light is sunlight. By direct correlation, the more time you spend in the sun, the more blue light exposure you will have. Technology includes many opportunities for additional blue light exposure. From indoor lighting to electronic devices, computers and TVs, we have a constant influx of blue light. Although these man-made forms of blue light are significantly less potent than sunlight, the long-term effect is still a concern to your eye doctor, and should be of consideration to you.
Not All Blue Light is Bad
Blue light exposure in moderation is actually good for you! It is known to have many benefits on the body and the psyche. For example, blue light helps the body make necessary Vitamin D. It also helps improve cognition, including memory and alertness. Blue light can also help boost a positive mental state. This is why light therapy is often prescribed for those affected by seasonal affective disorder (SAD). Like it’s acronym, SAD causes a seasonal depression due to reduced exposure to sunlight.
Timing is Everything…
Exposure to blue light helps set the body’s sleep-wake cycle. In terms of those who are awake during the day and asleep at night, exposure to blue light during the day helps foster a healthy circadian rhythm. However, blue light at night, especially at bedtime, can have the opposite effect, causing circadian rhythm disruption. As many of us do, reading on our cell phone, tablet or other electronic device can make it harder for the mind and body to wind down for sleep.
When Blue Light is Harmful
Incredibly, the human eye lens naturally blocks the retina from nearly all UV radiation from the sun. Although the eyes were designed to protect the retina from UV radiation, nearly all blue light rays reach directly through to the back of the eye. (There are other harmful effects of UV on the eye including cataract, pinguecula, pterygium, etc., therefore, sunglasses that block 100% of UV are recommended.) These blue light rays have been shown to damage the light-sensitive cells in the retina, much like macular degeneration.
Macular Degeneration is a serious eye disease, causing irreversible partial to full blindness. It has not yet been determined how much is too much when it comes to blue light exposure, so caution is advised to prevent any irreversible damage.
Aside from permanent damage, too much man-made blue light is known to increase Digital Eye Strain. It is more difficult for the eye to focus while exposed to emitting blue light because its shorter wavelengths scatter more readily, causing what is considered to be “visual noise.” This “noise” is draining on the mental and visual system.
How to Reduce Unnecessary Blue Light Exposure
- Use a blue light filter on your phone or device, especially at night.
- Google Play offers an app called ‘Bluelight Filter for Eye Care,’ stating: “This app adjusts your screen color to reduce the blue light and helps your eyes to relax, making it easier for you to fall asleep.”
- Use special-purpose glasses designed to reduce blue light exposure. These are sometimes referred to as computer glasses, although you do not need to have an Rx or visual correction, just the specific lens or lens coating known as Blue Light Lens Technology. Of course, these are available with a visual prescription for those who need it. Some of these lenses have a yellow tint to them, but there are clear options available.
- Maintain the farthest workable distance between you and your blue-light device. Remember: Visible light, and therefore blue light, is electromagnetic radiation. The closer one is to the source of radiation, the stronger the effects of it are.
At Eyes For Life in Spokane, WA, our doctors and opticians specialize in selecting the right type of vision correction and lens features for your eye needs. We also believe in educating our patients and offering them the very best in service and products. Ask about Blue Light Lens Technology at your next eye appointment, or stop in and see an optician today!