I’m in Tennessee, and I’ve bought prescription eyeglasses on-line several times. The site just asks you to fill in the numbers off the prescription form. I’ve had no trouble at all, and no request to see tthe actual prescription.
Also, I don’t know if this is state law or what, but when I got my last eye exam, the optometrist (is that right?) made a point of giving me my prescription to take with me. I don’t recall her exact words, but she gave me the impression that it was my legal right to have that; I had the feeling she was going out of her way to comply with some regulation.
By the way, GlassyEyes.com is a big proponent of getting glasses on-line and often links to special deals and discounts. The guy is not affiliated with any retailer and the site has reviews of the various outlets and such. If you need new glasses, I’d start there.