Does your skin need blue light protection from your devices?

From your phone or screens? Probably not.

When examining the results of studies looking at the effect of visible light, like blue light, we need to be really focused on the context.

Studies that have shown a decrease in collagen, an increase in free radical production, or an increase in cell death…have been done on human skin cells in a petri dish.

Those results will probably not translate to our skin.

Our skin has more layers, including the epidermis. The epidermis contains a distribution of melanin. Melanin absorbs visible light like blue, green, and red light.

Almost none of the effects observed in human skin cells in a petri dish have been found in human skin.

The big exception is hyperpigmentation, which has been observed in people with deeper skin tones (Fitzpatrick phototype 3 and greater).

But there’s a big and bright caveat…

That caveat is irradiance. There’s a difference between a dimly lit light and a brightly lit one, but somehow many articles on the topic forget about this. I don’t think it’s much of a stretch to say that the sun is brighter than your phone.

One experiment that showed hyperpigmentation in people with deeper skin tones used a blue light dose of 99 joules per square centimeter of skin. That’s estimated to be about one-and-a-half to two-and-a-half hours of direct sunlight in the summer.

But the light from a screen? You’d need about 2000 hours to get that same exposure and that’s assuming you’re holding the screen close to your skin.

The brightest TV screens at a distance of 30 cm (about 12 inches) from your face are delivering about 1/200th (0.5%) of the blue light from the sun.

Irradiance also follows the inverse-square law, so doubling the distance from that bright TV screen to 60 cm means you’re getting 1/4th of the energy or about 1/800th (0.125%) of the blue light from the sun.

Unlike UV light, there’s also no standard for blue light protection like SPF. It’s difficult to compare products, ingredients, methods of protection, and their effectiveness.

Many of us are already using sunscreens, pigments, and antioxidants which may help.

For those with deeper skin tones who are concerned about hyperpigmentation, remember irradiance. Be sun-safe when you’re out on a bright summer day.

Watching a video or gaming?

You can just chill.

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