Blue light is complicated, as it is both good and bad for us.
Whether you’re stepping outside and bathing in sunlight or you’re turning on a light indoors, both of these activities involve contact with blue light.
Sunlight alone contains yellow, orange, red, green and blue light, including many in-between shades of these colors. There are two different types of wavelengths:
- Long Wavelengths – Contain less energy
- Short Wavelengths – Contain more energy
Colors on the red end of the light spectrum are long wavelengths and colors on the blue end are short, which means they have more energy.
While too much sunlight can cause sunburn, not enough natural sunlight can produce Vitamin D deficiencies. One-third of visible light is a type of blue light or high-energy visible light. Blue light has both benefits and concerning dangers, as highlighted below.
1. Blue Light Surrounds Us
Blue light does surround us, and it is everywhere. Whether it’s blue light from the sun or a human-made source, such as indoor lighting, electronic devices or televisions, escaping blue light is impossible.
2. Makes the Sky Appear Blue
Short-wavelength, high-energy rays that appear on the blue end of the light spectrum scatter and when they strike water and air molecules in the atmosphere, this scattering is what makes a cloudless sky appear bright blue.
3. Human Eyes Cannot Block Blue Light
While the cornea and lens can block UV rays from reaching the retina, nearly all visible blue light goes through the cornea and can reach the retina.
4. Blue Light Exposure is Linked to Macular Degeneration
Blue light exposure penetrates to the retina, which means that too much can damage the light-sensitive cells in the body. This change can cause macular degeneration, which may lead to permanent, irreparable, vision loss. While this doesn’t happen overnight, cumulative exposure to blue light concerns medical professionals.
5. Blue Light Causes Digital Eye Strain
Short-wavelength, high energy blue light emitted from electronic devices scatters more than other visible light. Because these devices emit high amounts of blue light, the noise from the blue light reduces contrast, which can cause digital eye strain. Studies show that blue light blocking glasses, such as BluTech Lenses, can help increase contrast and ease the eyes, making it easier to view digital devices for extended periods of time.
6. Cataract Surgery
Cataract surgery replaces the lens, and since this lens is new, patients that have undergone cataract surgery may benefit from eyeglasses that have special blue light blocking filters.
7. Not All Blue Light is Negative
Not all blue light is bad for our bodies. People that suffer from Seasonal Affective Disorder, otherwise known as SAD, benefit from receiving significant amounts of HEV blue light rays in the morning hours. Blue light can also help jump-start the body’s natural circadian rhythm, especially if people have a difficult time waking up.