Blue Light vs Your Eyes



What is blue light?

Sunlight contains red, orange, yellow, green and blue light rays and many shades of each of these colors, depending on the energy and wavelength of the individual rays Combined, this spectrum of colored light rays creates what we call “white light” or sunlight.

The light spectrum

There is an inverse relationship between the wavelength of light rays and the amount of energy they contain. Light rays that have relatively long wavelengths contain less energy, and those with short wavelengths have more energy.

Rays on the red end of the visible light spectrum have longer wavelengths and, therefore, less energy. Rays on the blue end of the spectrum have shorter wavelengths and more energy.

Blue light rays with the shortest wavelengths (and highest energy) are sometimes called blue-violet or violet light.

Blue light generally is defined as visible light ranging from 380 to 500 nm.

Virtually all visible blue light passes through the cornea and lens and reaches the retina.

The good and bad of UV

UV rays have higher energy than visible light rays (including blue light), which makes them capable of producing changes in the skin that create a suntan. The bulbs in tanning booths emit a controlled amount of UV radiation specifically for this reason.

Too much exposure to UV causes a painful sunburn — and even worse, can lead to skin cancer. These rays can also cause sunburned eyes — a condition called photokeratitis or snow blindness.

But ultraviolet radiation, in moderation, also has beneficial effects, such as helping the body manufacture adequate amounts of vitamin D.

Blue light is all around you

Sunlight is the main source of blue light and being outdoors during daylight is where we get most of our exposure to it. But there are also many man-made, indoor sources of blue light, including fluorescent and LED lighting and flat-screen televisions.

Most notably, the display screens of computers, tablets, smartphones, and other digital devices emit significant amounts of blue light.

The amount of HEV light these devices emit is only a fraction of that emitted by the sun. But the amount of time people spend using these devices and the proximity of these screens to the user’s face have many optometrist and other health care professionals concerned about possible long-term effects of blue light from computers and phones on eye health.

Why you want to block blue light

The fact that blue light penetrates all the way to the retina (the inner lining of the back of the eye) is important, because laboratory studies have shown that too much exposure to blue light can damage light-sensitive cells in the retina.

This causes changes that resemble those of macular degeneration, which can lead to permanent vision loss.

Blue light scatters more easily than other visible light, it is not as easily focused. When you are looking at computer screens, TVs, cellular phones, and other digital devices that emit significant amounts of blue light, this unfocused visual “noise” reduces contrast and can contribute to eye strain.

Too much blue light late at night (watching TV or staring at your phone or computer for example) can disrupt your sleep cycle, potentially causing sleepless nights and daytime fatigue.

How ZOOMe blue light blocking glasses can help

Blue light blocking glasses from ZOOMe can help to reduce blue light exposure from digital devices. These special-purpose glasses are available without a prescription if you have no need for vision correction or if you routinely wear contact lenses to correct your eyesight.

See your eye doctor or optician for more advice on the best computer glasses for viewing your screens and protecting your eyes from blue light.