Question

Myophia correction doubt

I understand what myophia is.. but my doubt is when it is corrected using a diverging lens.. all it does is that it brings the far objects to the far point

for example.. if a person is myophic with 100cm as far point (meaning he cannot see clearly anything farther than 100cms).. then usng divernging lens we make sure any object at infinity is brought to 100 cm .

what i don't understand is.. now the near objects will be even closer.. and might get closer than the near point of the eye (25cm).. does this mean when myophic person has to see somthing near by

Answer 1

he has to remove his glasses?

Answer 2

@yrelhan4

Answer 3

No. I'm myopic.

Answer 4

when reading book!?? what about that!?? don't you have to remove glasses?!? what is your power?!

Answer 5

My power is -1.00
And no, I don't have to remove glasses when I read a book (a rare event).
People have this misconception about the near point of an eye.
The near point is not the point before which you can't see clearly. I can see the tip of a pen-nib perfectly clearly (if I concentrate hard enough) even when it's about 3 cm from my nose. It's just the point before which there is considerable strain on your eye.
But you are right in saying that the nearest point (i.e. 3 cm for me) shifts further away from you. For example, when i wear my glasses, my nearest point shifts to about 5 cm.

P.S. That means that a myopic person strains his eye more than a person with normal vision while reading a book.

Answer 6

Ok.. that makes sense..
so its WISE to remove glasses ? :P

Answer 7

Your power is 1 D.. which means the focal length is 1m

wow that means you are myophic with a far point of 100cm!.. ? :D

Answer 8

I guess...but text does seem clearer when I have my glasses on. I don't know if that's because my eyes are used to wearing glasses or not.

Answer 9

anything farther than 100cm and you can't see.. :D

Answer 10

hmmm damn.. i should have done more research before my lecture tomo :P.. but its ok.. lemme not get too detailed :D

Answer 11

That's not true. Anything farther than 100 cm is not clearly focussed on my retina and starts to appear blurry.

Answer 12

yea yea.. thats what i meant.. can't see properly! ^_^

Answer 13

i had one more doubt..
if you are hyperobic

then you are wearing converging lenses

so if you now look at far away objects.. (which would be outside the focal length).. they would start giving you INVERTED images right???

Answer 14

so you would see blurry inverted images ??

i wish i had a reading glass somewhere near by!! :(

Answer 15

@rajathsbhat

Answer 16

No. A reading lens effectively makes you myopic (think about it). When you try to see the head of a pin from far away using a reading glass it just appears blurry because it produces an image that is sort of a patch on the retina.

Since you can consider the pin as a collection of such points, each point on the pin produces a patch of an image on the retina and as a result, you see a blurry pin. I image of the pin is inverted. That's of course how every image is.