Does screen time (blue light) age your skin?

Blue light can damage skin cells in the lab. Cell and animal studies show that it breaks down collagen, inhibits the production of new collagen, and at high doses causes significant damage to the power plants of cells (mitochondria). However, these are laboratory conditions using doses that no ordinary screen ever reaches.

The only clinical study that directly examined skin-ageing markers in humans (8 volunteers, five treatments) found no evidence of DNA damage or early ageing. Reassuring, but with so few participants and such a short duration, this is not a definitive answer.

The clearest effect demonstrated in humans is skin discolouration: a randomised study involving 33 women observed a visible increase in pigmentation after repeated exposure, particularly in people with a darker skin type. The light doses used in this study were higher than those emitted by a screen, however, so how relevant this is to everyday computer use is uncertain.

Niacinamide (a form of vitamin B3, found in many common skincare products) was shown in that same randomised study to reduce blue-light-induced skin discolouration. The study was funded by the manufacturer of this ingredient, which may have influenced the results.

Interestingly, blue light also has a beneficial side in medical applications: at the right settings it works as an acne treatment through an antibacterial effect. This shows that the dose and the context make the difference, not the light itself.