# How do you translate a glasses prescription to XX/XX vision ?



## LizaBear (Feb 1, 2003)

hmm - the question isn't very clear is it ?

I know what my glasses prescription is (-4.25 / -4.25), but what does that mean in terms of vision.

I know it's far from 20/20, but what is it roughly ?


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## LoriG (Feb 27, 2003)

I don't know how to translate it, but last time I was getting an eye exam, I asked the doctor. My contacts are -4.00 in each eye, and he said my vision was 20/900. Lovely! LOL


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## LizaBear (Feb 1, 2003)

Quote:


Originally Posted by *LoriG*
I don't know how to translate it, but last time I was getting an eye exam, I asked the doctor. My contacts are -4.00 in each eye, and he said my vision was 20/900. Lovely! LOL

Yikes ! Somehow, I'm not surprised at that though.


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## applejuice (Oct 8, 2002)

I am guessing the - corrections are for myopia, concave lenses, (nearsightedness); I do not know how 20/900 translates to -4.00

Conversely, the + corrections are for hyperopia, convex lenses (farsightedness);

I have +200 for presbyopia, Greek for "old eyes";









Waiting for the bifocal, trifocal dx to kick in...


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## shelbean91 (May 11, 2002)

I'm not sure how the numbers translate, but 20/900 seems wierd for -4.0, as my left eye is pretty close.

I know 20/20 stands for being able to see clearly something that is 20 (cm? mm? not sure the measurement) from 20ft away. So the 20/900 would be able to see something that is 900 (something measurement) from 20 ft away.

If you can't read the big E on the eye chart, your vision is worse than 20/200, from what I recall.


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## shelbean91 (May 11, 2002)

Here's a better explanation:

http://science.howstuffworks.com/question126.htm


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## CarrieMF (Mar 7, 2004)

Quote:

I know what my glasses prescription is (-4.25 / -4.25), but what does that mean in terms of vision.
It's better than mine.lol

right eye is -6, left is -8. I can't see the big E. It's a blur of 3 lines.

My 7yo is getting glasses, they should be in next week. Hers are a -1 and a -1.25.

My moms eyes are worse than mine. My actual vision hasn't changed in 8 or 9 years but my astigmatism is getting worse which makes me need new lenses(so do the scratches,lol). Girls typically don't need glasses until they're 10ish so my dd is doomed to have my eyes.

Kids inherit 60% of their vision from their mother.

When I had my eyes checked last week with the correct lenses(mine aren't 100% due an astigmatism but it doesn't affect my vision) I can see 20/13 which is farsighted where a person ideally is. It's better than perfect vision. Without the astigmatism added I can still see 20/13 with my current prescription but it's slightly fuzzy.

The bigger the 2nd number the more you can't see far away(nearsighted).

Something to watch for it you have eyes like mine is spots in your vision or floaters. It's a sign that the virtous gel in your eyes is falling due to it being elongated. This started for me a few years ago, I don't see them anymore so it's fallen below the level of my eyesight. It is very common in nearsighted people. Unfortunatly it also increases the risk of retina detachment as it's pulled away too. So if you see any black curtains get into an eye specialist ASAP.


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