2 doctors weighed in:
How does sunscreen actually work?
2 doctors weighed in

Dr. Michael Fisher
Dermatology
1 doctor agrees
In brief: Sunscreen
Sunscreen combines organic and inorganic chemicals to filter the light from the sun so that less of it reaches the deeper layers of your skin.
Like a screen door, some light penetrates, but not as much as if the door wasn't present. Sunblock, on the other hand, reflects or scatters the light away so that it doesn't reach the skin at all.

In brief: Sunscreen
Sunscreen combines organic and inorganic chemicals to filter the light from the sun so that less of it reaches the deeper layers of your skin.
Like a screen door, some light penetrates, but not as much as if the door wasn't present. Sunblock, on the other hand, reflects or scatters the light away so that it doesn't reach the skin at all.
Dr. Michael Fisher
Dr. Michael Fisher
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