Why does looking directly at the sun damage your eyes?

Epicurus0319@sopuli.xyz to No Stupid Questions@lemmy.world – 69 points –
31

Because the lens in your eye you use to focus, acts like a burning glass, and burn the back of your eye, where what you see is focused at.

It's like using a magnifying glass to burn an ant on the pavement, but the sun is you, you're the ant, and the sun is using your eyeball as the magnifying lens

The sun is still the sun in this comparison. Its not like "you" is the source of light here. The back of your eye is the ant, and the lens of your eye is the magnifying glass.

1 more...
1 more...
1 more...

Cuz there is a secret alien weapon inside of it and the gov doesn't want you to see it, so sun's glaze blinds you

Because the sheer amount of energy going directly on your retina will burn a hole through it. It'll also damage the photo receptor cells at the back of the eye.

https://en.m.wikipedia.org/wiki/Photic_retinopathy

Photic retinopathy generally goes away on its own over time, but there is no specific treatment known to be reliable for speeding recovery.

Thank god to know it gets better over time. I was a dumb, dumb kid.

(side note: Still dumb, just not a kid anymore)

The second part I knew, but the first part I did not. Rest assured, I never let this happen, my parents always made sure I knew not to look at the sun

Wait. What?!?

I've spent the last 16 years avoiding direct eye contact with my son for fear of eye damage.

On a related note, why is it that looking at the sky when there's a lot of light, if I use both eyes it hurts, but if I keep one closed I can see the sky just fine?

That's actually a bug; your brain averages light levels across both eyes when deciding how much to flinch.

Don't do it - you're basically exposing yourself to potentially damaging light levels in the eye you keep open.

One desensitized eye

I'm not sure, it doesn't matter which one I close

Pure conjecture, but maybe one overloaded eye is easier to handle than two?

There is physical damage of heating the retina with focused light, and there is chemical damage of depleting the reactions that normally occur when light is translated into neural signals in the retina.

Wikipedia says that the heating from the focused light is minimal because the retina is surrounded with fluid, similarly to how a balloon filled, even partially, with water won't pop over a candle flame. However, the light itself is damaging, as far UV is ionizing radiation and can rip apart the molecules making up your cells.