ELI5; Why/ how do our eyes interpret bright light as painful?



For example being used to a dark room, and then walking into another that’s much brighter and having a pain response while adjusting to the new lighting.

In: Biology

In a dark room, our pupils dilate to let in more light so we can see better. Pupils also constrict in a bright room to help cut down the amount of light going to the retina. If you go from a dark room to a light room, your dilated pupils let in a large amount of light which damages the retina because of how sensitive they are.

Because it is quite literally hurting you.

Having too much light hit your retina will damage it, so your body uses one of the few communication channels it has to your consciousness – pain – to tell you that “bright light bad”.

To protect us from sun damage maybe, as they adjust ?

I dunno if i would call it exactly as pain..it’s feels more of like a natural response of our body to close our eyes when bright light is concentrated at it.. just like gaging is a natural response.

I have a fascination with the sun and I certainly did not have any pain when i used to look directly at it for 5 to 10 seconds when i was a kid.. you do start seeing with weird colors and it’s like a whole different world though.

I’m not encouraging anyone to do it unless you want permanent eye damage but that’s one of my experiences of bright light.

Simply there is a ton of energy in light, ever held a magnefying glass focussed on some dry grass under the sun? Now obviously that is the extreme case, but this is what is happening in your eye through it’s own lens.