eli5 why does our sight and hearing go with age? and do our other senses get worse too?
In: 12
Optician here: When we are born our eyeballs are a certain size/shape and that never changes (a newborn eyeball is the same size it will be as an adult).
Everything we see is light energy that in basic terms travels to your pupil onto your retina and then your optic nerve send the information to your brain. *FUN FACT: Your optic nerve sees everything upside down and your brain auto corrects it to right side up.
With perfect vision that all happens smoothly. So why do we eventually need glasses?
Inside our eye we have a lens (like in a camera) that can essentially flex to make images clearer. If I recall it can flex 46 units initially (or close to that). But as we get older the lens become stiffer and can’t compensate anymore. By the time we are in our 40’s that number drops down to about 20, which is why folks usually need reading glasses at that point. By the time we hit 65 it’s down to 5 units…basically it can’t flex to zoom in and out at all at that point.
So thats why we all eventually end up in glasses. I can explain why people need prescription glasses in general too I’d you’d like. 🙂
Hope that made sense.
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