Just wondering.Is it something to do with the lense in your eye not being able to focus properly or something?
I need to wear glasses because i can't see things far away. How is that different to needing glasses for reading a book or something
2006-11-20 07:02:59 · 7 answers · asked by ? 3 in Science & Mathematics ➔ Other - Science
1) The lens in the human eye is unflexed by the surrounding muscles when relaxed (looking @ far away things) & flexed to look @ close up objects. Our inside world today has many more close up objects & the lens gets distorted by being over used in this way - it can't go back to its original shape. That's nearsightedness. Its opposite, farsightedness, is the inability for the muscles to pull hard enough to bend the lens so that close up things can come into focus.
2) As people age, changes in the eye alter its shape & the ability to see far away improves slightly while close up sight degrades (starts around mid-40s) that's where bi-focals come from - to address this dual problem.
3) If the eyball is an uneven shape, then the lens is stretched unequally, or the light is slightly misdirected onto the retina; this is called astygmatism.
4) All three conditions are strongly affected by genetics.
;-)
2006-11-20 07:26:25 · answer #1 · answered by WikiJo 6 · 0⤊ 0⤋
over time, the lens in your eyes gets stressed from such activities that involve too much use of your eyes. such as reading in not so lit places, sitting very close to the tv, and even spending time in front of the computer. wearing glasses help focus your eyesight to a degree as if it was before you started having vision problems. but because vision problems are progressive, you need to have your eyes examined every year to see if the sight is getting worse. if you have had the same vision problem and you're over 18, you can get eye surgery to permanently correct your eyesight. if you think that glasses are too uncomfortable, you may want to consider wearing soft contact lenses.
2006-11-20 07:13:38 · answer #2 · answered by jqdsilva 3 · 1⤊ 0⤋
People have different sizes of eyes! Not kidding really, something I picked up in A-level Physics. Long-sighted people have problems converging light rays from far away objects whereas short-sighted people, the focus point (where light is converging) falls short of the retina (part of the eye where the light is focused). Glasses, contact lens etc. correct these problems by altering the light rays travelling into the eyes. Its too difficult explaining it on the 'net! Ask your physics teacher (if you have one!) or consult a good book on physics or optometry if you're really interested!
2006-11-20 07:10:47 · answer #3 · answered by saju_ahmed06 2 · 1⤊ 0⤋
the shape of the cornea is wrong or it doesn't flex properly ( age ) to focus
in your case the shape is the opposite of the other ( you are nearsighted the reading problem is farsighted ) in my case i need my glasses to see at a distance but i have to remove them for close work ( under 3 feet )
i am nearsighted and also the lens is becoming inflexible from age ( which is why people need bi or tri-focal lenses )
2006-11-20 07:04:40 · answer #4 · answered by Anonymous · 1⤊ 0⤋
i wear glasses too.the days of being called 4 eyes is over seems like every one wants to wear glasses now with or without a problem any i cant see stuff from far away also but i look cool in my 400 dollar dolce & gabbana glasses
2006-11-20 07:06:44 · answer #5 · answered by Anonymous · 0⤊ 2⤋
It's more to do with the structue of the eye itself.
2006-11-20 07:05:56 · answer #6 · answered by scruff 4 · 0⤊ 0⤋
no affence but i think its because people cant see good so they get glasses i would get contacts
2006-11-20 07:06:43 · answer #7 · answered by Anonymous · 0⤊ 2⤋
because their doc told them too
2006-11-20 07:04:27 · answer #8 · answered by girl with questions 2 · 0⤊ 2⤋