Every day, retinal specialists are asked about the risks from blue light emitted from electronic devices. (Retinal specialists treat conditions affecting the retina, a thin tissue at the back of the eye that is responsible for vision.) Many people ask whether blue light will increase their risk of age-related macular degeneration and blindness.
The short answer to this common question is no. The amount of blue light from electronic devices, including smartphones, tablets, LCD TVs, and laptop computers, is not harmful to the retina or any other part of the eye.
What is blue light?
Blue light is visible light with a wave length between 400 and 450 nanometers (nm). As the name suggests, this type of light is perceived as blue in color. However, blue light may be present even when light is perceived as white or another color.
Blue light is of concern because it has more energy per photon of light than other colors in the visible spectrum, i.e. green or red light. Blue light, at high enough doses, is therefore more likely to cause damage when absorbed by various cells in our body.
How do we perceive color?
Our perception of color relies primarily on four main light-sensitive cells: three cone photoreceptors and one rod photoreceptor. These cells reside within the retina.
During the daytime, the three cone photoreceptors actively sense light, and each has a peak sensitivity in either the blue, green, or red portions of the visible light spectrum. On the most basic level, our sense of color is determined by the balance of activity of these three cells. When the light is too dim to stimulate the cones, our sense of color is extinguished. We perceive the world in shades of gray because only one type of photoreceptor, the rod, is maintaining our visual function.
LED technology and blue light
Most incandescent light sources, like sunlight, have a broad spectrum of light. However, light emitting diodes (LEDs) produce relatively narrow peaks of light that are crafted by the manufacturer. This allows light from LEDs to be perceived as almost indistinguishable from white light, or daylight. (They can also be made to mimic traditional artificial light sources.).....READ MORE
More information from Harvard Health Publishing - HARVARD MEDICAL SCHOOL