Eli5: How does sunscreen prevent the skin from getting damaged by UV? Isn’t it eventualy absorbed into the skin?


Thank you for the answers guys, this is very interesting to me!

In: Chemistry

It blocks the UV in sun light. Like aluminum foil can block light. UV waves are small enough to physically damage your skin cells DNA

https://en.m.wikipedia.org/wiki/Sunscreen has a nice photo you can see where they applied sun screen.

It depends. Some sunblock reflects uv back away from the skin. In this case none of that energy is absorbed by the body. Others absorb it and turn it into heat energy. The heat energy might cause some discomfort when transferred into the skin but won’t cause ionization of organic molecules which is what causes sun burn. Understand sun burn isn’t the same as a normal burn like you might get from a stove top.

Sunscreen protects your skin because the UV Rays get absorbed by the chemicals/molecules of the sunscreen, instead of the chemicals/molecules that make up your skin.

Some of it is absorbed into your skin, but most of the sunscreen gets rubbed/washed off of your body.

Thank you OP for asking this question and thank you to everyone who answers, because I was curious and didn’t know this either

Eventually, but you reapply and the barrier is replenished and the UV light can’t get in anymore

That’s why when we were kids (those of us with parents that cared enough lol) it seemed like we were always applying sunscreen