We’ve all heard the warnings…too much blue light is bad for you. Avoid blue light before bedtime. Excess blue light can harm your eyes. But why the bad rap?
Like ultraviolet radiation, visible blue light—the portion of the visible light spectrum with the shortest wavelengths and highest energy—has both benefits and dangers. Blue light in and of itself is not bad, but there are some important things you should know.
1) Blue light is everywhere.
Sunlight is the main source of blue light, but there are also many man-made, indoor sources of blue light, including fluorescent, LED lighting, and flat-screen televisions. The display screens of computers, tablets, and smartphones emit significant amounts of blue light, but it is only a fraction of that emitted by the sun. However, the amount of time we spend on these devices, and the proximity of the screens to the face, have many eye doctors concerned about possible long-term effects of blue light on eye health.
2) The open eye is not very good at blocking blue light.
Anterior structures of the adult human eye (the cornea and lens) are very effective at blocking UV rays from reaching the light-sensitive retina at the back of the eyeball. In fact, less than one percent of UV radiation from the sun reaches the retina, but virtually all visible blue light passes through the cornea and lens and reaches the retina.
3) Blue light exposure may increase the risk of macular degeneration.
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. Although more research is needed, many eye care providers are concerned that the added blue light exposure from computer screens, smartphones, and other digital devices might increase the risk of macular degeneration later in life.
4) Blue light contributes to digital eye strain.
Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easily focused. When you’re looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused visual noise reduces contrast and can contribute to digital eye strain. Research has shown that lenses that block blue light with wavelengths less than 450 nm (blue-violet light) increase contrast significantly. Therefore, computer glasses with yellow-tinted lenses may increase comfort when you’re viewing digital devices for extended periods of time.
5) Where is the increased exposure to blue light coming from?
The evolution in digital screen technology has advanced dramatically over the years, and many of today’s electronic devices use LED back-light technology to help enhance screen brightness and clarity. These LEDs emit very strong blue light waves. Cell phones, computers, tablets, and flat-screen televisions are just among a few of the devices that use this technology. Because of their wide-spread use and increasing popularity, we are gradually being exposed to more and more sources of blue light and for longer periods of time.
6) Not all blue light is bad.
So, is all blue light bad for you? Why not block all blue light, all the time? Bad idea. It’s well documented that some blue light exposure is essential for good health. Research has shown that high-energy visible light:
- Boosts Alertness
- Helps Memory
- Helps Cognitive Function
- Elevates Mood
In fact, something called light therapy is used to treat seasonal affective disorder (SAD) — a type of depression that’s related to changes in seasons, with symptoms usually beginning in the fall and continuing through winter. The light sources for this therapy emit bright white light that contains a significant amount of HEV blue light rays.
Also, blue light is very important in regulating circadian rhythm — the body’s natural wakefulness and sleep cycle. Exposure to blue light during daytime hours helps maintain a healthful circadian rhythm. But too much blue light late at night (reading a novel on a tablet, computer, or e-reader at bedtime, for example) can disrupt this cycle, potentially causing sleepless nights and daytime fatigue.
7) What about the Blue Lights used with the BrainTap headset?
The BrainTap headset uses a photo-modulated (pulsed, light emitting diodes) which are also used in low-level light therapy (LLLT).
It is important to remember that the BrainTap sessions are designed to be enjoyed with the eyes closed. Most of the issues we described above with blue light are about the amount of time spent with the eyes open viewing the screen on your computer, smart phone, TV, or in a room with your eyes open and getting blue light from a fluorescent or LED bulb.
8) What does NASA say about LED Light Therapy?
NASA studies demonstrate cells exposed to LED light therapy exhibit a 150% increase in cellular metabolism, suggesting enhanced cellular repair and vitality. Medical researchers across the globe are currently investigating a wide array of physiologic benefits produced by LED light therapy. LED light therapy is non-invasive, painless, and restorative. It is safe in the clinic or at home for all ages and skin types.
Would you like to experience the benefits of the BrainTap headset for yourself? Click here to find a location for a FREE DEMONSTRATION.