There have been countless scientific studies conducted stating overexposure to blue light can be harmful to our health, but how? 

One major way is through the damage it causes to the eyes and their photoreceptors - the cells in the retina. These respond to light and are uniquely adapted to function over a wide range of ambient light conditions. However, prolonged intense visible light exposure can lead to these cells becoming compromised. This is because the eye’s cornea and lens are unable to block or reflect the short wave, high-energy frequency of blue light, meaning it passes right through the eye and reaches the retina where it can damage the primary retinal cells and photoreceptors. Overtime, this may affect vision by prematurely aging the eyes as well as causing contrast issues, which makes the eye have to work harder to adjust, leading to digital eye strain.

Blue light-induced retinal damage is mainly caused by the production of reactive oxygen species (ROS) and lipofuscin. ROS are reactive molecules containing oxygen in the body and can be toxic to cells. A study suggests that the more a display device contains blue light, the more the ROS production causes dysfunction in the pigmented layer of retina and eventually results in cell death. 

Another way blue light is harmful is through the byproduct it creates in the eye. Called lipofuscin, a buildup of this byproduct in the macula can lead to age-related macular degeneration and thus impair the high definition centre of our vision.