# Do I need to know my eyeglass prescription to get cheaper glasses elsewhere? **URL:** \ **Category:** Factual Questions\ **Created:** [March 22, 2011, 8:45pm UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646 "2011-03-22T20:45:20Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Disheavel](https://avatars.discourse-cdn.com/v4/letter/d/e274bd/32.png) [@Disheavel](https://boards.straightdope.com/u/Disheavel)\ **Post date:** [March 22, 2011, 8:45pm UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/1 "2011-03-22T20:45:20Z")
I don’t want another eye exam, just another pair of cheaper glasses I don’t want to have to worry about as much, but I don’t know my prescription. So if I bring in only my glasses to somewhere like Target Optical, can they determine my prescription (no bifocals or anything complicated) and make new lenses? Or do I need to call my optometrist’s office and get the prescription numbers (Is this obnoxious to do?)? ---
**Author:** ![Icarus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/icarus/32/72_2.png) [@Icarus](https://boards.straightdope.com/u/Icarus)\ **Post date:** [March 22, 2011, 8:49pm UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/2 "2011-03-22T20:49:55Z")
> [@Disheavel](#): > > I don’t want another eye exam, just another pair of cheaper glasses I don’t want to have to worry about as much, but I don’t know my prescription. So if I bring in only my glasses to somewhere like Target Optical, can they determine my prescription (no bifocals or anything complicated) and make new lenses? Or do I need to call my optometrist’s office and get the prescription numbers (Is this obnoxious to do?)? Where I am, optometrists are required by law to provide you a written prescription. This is so you can shop for glasses wherever you like. Although, they will also use a 2 years expiration date on the prescription to kinda force you to get a new exam if the last one was over 2 years ago. ---
**Author:** ![Wakinyan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wakinyan/32/352_2.png) [@Wakinyan](https://boards.straightdope.com/u/Wakinyan)\ **Post date:** [March 22, 2011, 8:55pm UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/3 "2011-03-22T20:55:02Z")
I live in Sweden, I had my eye examination at one optician and then I went to another to buy my glasses (because the company I work for turned out to have an agreement with the later). Via “the computer” the later got the prescription from the former and it all went from there. ---
**Author:** ![Jenaroph](https://avatars.discourse-cdn.com/v4/letter/j/e8c25b/32.png) [@Jenaroph](https://boards.straightdope.com/u/Jenaroph)\ **Post date:** [March 22, 2011, 9:08pm UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/4 "2011-03-22T21:08:12Z")
How long ago was your last eye exam? By law your eyeglass prescription has an expiry date of no less than one year. The FTC[requires](http://www.ftc.gov/opa/2004/10/contactlens.shtm)prescribers to give clients a copy of their eyeglass (and/or contact lens) prescription after an exam. If you didn’t keep it, and it was less than a year ago, it couldn’t hurt to ask your eyecare provider for another copy. ---
**Author:** ![Baffle](https://avatars.discourse-cdn.com/v4/letter/b/dec6dc/32.png) [@Baffle](https://boards.straightdope.com/u/Baffle)\ **Post date:** [March 22, 2011, 9:09pm UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/5 "2011-03-22T21:09:13Z")
The optician can “read” the prescription on your current lenses by analyzing the index of refraction. From that, he can make an identical pair. No need for a visit to an optometrist, though you might not otherwise notice if your eyes have changed since your last visit. They’re also good at checking for eye disease. But if it’s just new glasses you need, go that route. ---
**Author:** ![Disheavel](https://avatars.discourse-cdn.com/v4/letter/d/e274bd/32.png) [@Disheavel](https://boards.straightdope.com/u/Disheavel)\ **Post date:** [March 22, 2011, 9:34pm UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/6 "2011-03-22T21:34:31Z")
So it looks like a call to my old optometrist is worth a shot and then off to the cheap place. My old glasses are perfect and would prefer to wear them more, but can’t afford the $300+ to replace them if something goes badly. Thanks, all. ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [March 23, 2011, 2:14am UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/7 "2011-03-23T02:14:43Z")
Nothing to it, stick the glasses in the machine and it reads out the prescription. Then make new lenses. Except for the legal matters of having to have a doctor’s prescription. ---
**Author:** ![freckafree](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/freckafree/32/3050_2.png) [@freckafree](https://boards.straightdope.com/u/freckafree)\ **Post date:** [March 23, 2011, 2:19am UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/8 "2011-03-23T02:19:26Z")
If you’re getting your eyeglasses online, make sure the written prescription you get from your optometrist includes the measurement for pupil distance. If you take your prescription to a brick-and-mortar shop, they will measure your pupil distance, so optometrists sometimes don’t automatically include it. But an online shop needs you to provide that measurement when you order your glasses. ---
**Author:** ![drachillix](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@drachillix](https://boards.straightdope.com/u/drachillix)\ **Post date:** [March 23, 2011, 2:21am UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/9 "2011-03-23T02:21:28Z")
I just went and got an exam then ordered them from zennioptical. They are in hong kong and apparently they don’t care about the ex, you fill in the form with the info and they ship them. $28 vs the $235 the optometrist wanted. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [March 23, 2011, 2:33am UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/10 "2011-03-23T02:33:48Z")
> [@drachillix](#): > > I just went and got an exam then ordered them from zennioptical. They are in hong kong and apparently they don’t care about the ex, you fill in the form with the info and they ship them. $28 vs the $235 the optometrist wanted. A problem with zenni is you need your pupil distance which isn’t normally written on your Rx. I had to go into lenscrafters and get mine done by a technician so I could fill out the order. I see someone already mentioned PD though. Plus if you have a complex Rx then doing it at zenni could be a hassle. Luckily I just have myopia so mine was relatively easy to fill out. But it can be confusing since it is all written in medical lingo. Plus zenni’s glasses don’t seem to last very long, at least to me. I haven’t had a pair last more than a year, some broke in a month. A pair I bought at lenscrafters for $80 lasted me almost 10 years (my Rx barely changed in the last 10 years or so). For my next pair I’m just going to get a special at pearle or some other retailer. ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [March 23, 2011, 3:08am UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/11 "2011-03-23T03:08:57Z")
> [@Disheavel](#): > > Or do I need to call my optometrist’s office and get the prescription numbers (Is this obnoxious to do?)? Se the law at [16 CFR 456.2.](http://edocket.access.gpo.gov/cfr_2002/janqtr/16cfr456.2.htm) ---
**Author:** ![Superhal](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Superhal](https://boards.straightdope.com/u/Superhal)\ **Post date:** [March 23, 2011, 8:35am UTC](https://boards.straightdope.com/t/do-i-need-to-know-my-eyeglass-prescription-to-get-cheaper-glasses-elsewhere/575646/12 "2011-03-23T08:35:02Z")
Wow, why do you guys pay so much for glasses?