Blue Light Explained
Macular Degeneration Blue light (HEV) penetrates all the way to your retina and has been shown that too much exposure to blue light can damage light sensitive cells in the retina. This causes changes that are similar to those of macular degeneration, which can lead to permanent vision loss. Many eye care professionals have concerns that the blue light exposure from digital screens might increase a person's risk of macular degeneration later in life.
Digital Eye Fatigue Short wavelength, high energy blue light scatters more easily than other visible light and makes it not as easily focused. When you're looking at your digital screen that emit significant amounts of blue light, this unfocused visual light reduces contrast and can contribute to digital eye strain.
Sleep Disruption Blue light is very important in regulating circadian rhythm - your 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 can disrupt this cycle, causing sleepless nights and daytime fatigue. People who use their electronic devices before bed have a harder time falling and staying asleep.
Why Not Block All Blue Light?
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 and cognitive function and 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.