Sunburn, UV light, and eyes

[FIAT2LUX]

My understanding is that sunlight is mandatory for the health of the eyes. But my question, is how exactly is that the case when skin will burn if exposed for too long to direct sunlight. I understand that sunglasses cause problems by making one sensitive to light, but I don't quite understand how this works. Ideas?

[Shambles]

I don't follow you to be honest. Your skin needs sunlight aswell.... Vit D..

Yes it burns if exposed for too long, same goes with the eyes.. I'm sure.if you stare athe sun at midday for an hour you're over doing it.