How to find your eyeglass prescription without getting an exam

Want to freshen your face with a new pair of eyeglass frames? As you probably know, you can save a small fortune by ordering glasses online.

Just one wrinkle: You need to know your prescription. Sure, you can call your optometrist to get the numbers -- unless the office is closed. Or you just feel weird about asking because they'll know you're shopping elsewhere.

Thankfully, if you have a pretty basic prescription (meaning they're not bifocals, progressives or Coke-bottle lenses), there's a free tool from GlassesUSA.com that can scan your current glasses. I took it for a spin with my son's glasses and the results matched his current prescription.

And according to GlassesUSA.com, the results are "in line with the standard range of deviation as in any doctor's office" -- though this isn't meant to take the place of an eye exam. Indeed, if you haven't had your vision checked in a year or more, it might make sense to schedule an appointment. 

But if you just want a quick and easy way to find out what kind of lenses you have right now, here's how:

Step 1: Armed with your current glasses, your phone and a credit card (which is used for sizing, not payment), plunk down in front of your computer and point your browser to www.glassesusa.com/scan.

Step 2: Enter your phone number or email address to receive a link for the GlassesUSA app.

Step 3: Once you've installed the app, following the guided tutorial. You'll first need to scan an onscreen QR code, then hold the credit card up to the screen and scan that. From there you'll hold your glasses between the phone and the screen for various readings. It ends with a pupillary-distance (PD) scan, which rather amusingly requires you to hold the card up to your forehead.

It's a pretty simple process that takes all of about 10 minutes. When you're done, you'll be asked to create a GlassesUSA.com account, at which point you should immediately see your prescription.

And that's it! Armed with that data, you can order lenses and frames from anywhere. Just take note that the app doesn't store any of this information; if you want to retrieve it later, you'll have to sign back into your GlassesUSA.com account in a browser.