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Need to convert contact lens 'scrip to 20/20...?

Discussion in 'The Lounge' started by newyorkin, Mar 5, 2007.

  1. newyorkin

    newyorkin 1 ton status

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    I need to find out what my vision is in terms of 20/20, 20/40, etc.

    Do any of you guys know where I can find some kind of calculator or formula where I can plug in my contact lens prescription to find out what my vision is without correction?


    Gracias...
     
  2. 55Willy

    55Willy 3/4 ton status

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    whats on the package that your lenses came in?
    Mine stated abunch of numbers for my astigmatism( off center ) for all the weights and placements but it still had '90 on one and '80 on the other as I was 20-80 and 20-90 but that was 4 years ago and I haven't worn a contact in one of the eyes since. and my other lenses is 3 years old... i think it's just a piece of plastic i put in my eye every morning as there couldn't be any correction going on with one that old,LOL.
     
  3. mikey_d05

    mikey_d05 1 ton status GMOTM Winner

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    Visual acuity and diopters of correction are totally different systems that don't have any solid correlation. Two people that have the same correction lenses can have different visual acuities (IE 20/30 and 20/40)

    That said, for rough guesstimate purposes, one diopter of correction is equal to 20 feet of visual acuity. Sooo....if you have to guess at it, + 1.00 = 20/40, + 2.00 = 20/60, etc.
     
  4. newyorkin

    newyorkin 1 ton status

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    Uhhh...so anyone have a calculator or something that can do this? :D

    Thanks, it looks like I'm going to have to bite the bullet and take my chances without knowing ahead of time...
     
  5. dogdaysunrise

    dogdaysunrise 1/2 ton status

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    Thats too many big smart words for the lounge. Smells like tech to me... :D
     
  6. mikey_d05

    mikey_d05 1 ton status GMOTM Winner

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    What do you need it for? I'd be glad to sneak you into my dad's office and use the autorefractor to get you in the ballpark, but that's obviously not viable.

    Sorry, but there just isn't a hard and fast relationship between your personal vision and the correction built into your lenses.
     
  7. newyorkin

    newyorkin 1 ton status

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    Yeah I get that, I was trying to be facetious about the calculator...

    I need to know because I need to meet certain minimum fitness levels to qualify for something I'm trying to get. Eyesight is the only thing I'm worried about... If I'm automatically out of the running because of my eyesight, it would be best to know now instead of when they test me in 6 months. That way I can know before dropping cash on other things related to qualifying, or I may rush into lasik just to need less correction, and then qualify.
    I think the minimum was 20/80 without correction. I have bad vision, but I have no idea if it's worse than that or not. I can still see shapes and colors without contacts/glasses... :haha: :haha:

    Ha ha, thanks, I appreciate the offer. Can I swing by around 5? :rotfl: :rotfl:
     
  8. 55Willy

    55Willy 3/4 ton status

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    you have any friends with perfect vision? the difference of 20/20 vs 20/80 is huge. as stated I'm 20/80 in one eye and 20/90 in the other without my contacts in I see no shapes everything is just color fading to color theres no depth basicly.

    i'm not sure how accurite they are but the eye glasses at soem of the stores have the little eye chart with the floor marked that would atleast get you in the ball park.
     
  9. newyorkin

    newyorkin 1 ton status

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    I think my wife has 20/20. I should just go to the optics store I use for my contacts and test it. It's just a big pita to take out my contacts in the middle of the day. Seems like I can never get them back to that morning-set comfort level.
     
  10. BigBen

    BigBen 1/2 ton status Premium Member

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    As far as I know... the 20/80 means you need to be able to see at 20 feet what 'normal' person can see at 80 feet. Or at 1/4 the distance. It's not for defining prescriptions, just giving you a good relative reference for vision.

    If I wanted a quick read on what I was, I'd print out this:

    http://www.i-see.org/block_letter_eye_chart.pdf

    Check the letter size (instructions on the first page) to make sure it is right.

    If you can honestly read the 200 ft letter at 50 feet, or the 100 foot letter at 25 feet (etc) (Without glasses) I would think you have a good chance of passing a basic 20/80 test.

    This is a completely uneducated opinion (I'm an engineer, not an eye doctor:D ), but it's how I would interpret what you've been mentioning.
     

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