What Is Blue Light?

Blue light is a portion of the visible light spectrum with wavelengths between approximately 400 and 500 nanometers (nm).

It is emitted by natural sunlight as well as artificial sources such as LED lighting, computer screens, televisions, smartphones, tablets, and other digital devices. Although referred to as “blue” light, it is not always perceived as visibly blue.

Blue light has a shorter wavelength and higher energy compared to other visible light wavelengths.

Research shows that exposure to blue light in the evening can influence the body’s natural production of melatonin, the hormone that helps regulate sleep. This is why nighttime screen exposure is commonly discussed in relation to sleep disruption.

Blue light is also able to pass through the front of the eye and reach the retina, the light sensitive tissue at the back of the eye. Some laboratory and experimental studies have observed that very high intensity blue light exposure can affect retinal cells and produce changes similar to those seen in age related macular degeneration.

However, these findings are generally based on controlled laboratory conditions using exposure levels that may differ from typical everyday screen use. Research into the long term effects of cumulative blue light exposure on eye health is ongoing.