I have used Goggles4U (.com).
I have 2 pairs of glasses from them, purchased at different times.
If you get on their email list, they occasionally send out fantastic coupons (usually on holidays, like FourSevens).
The thing with them is, you will probably end up ordering several pairs over time, as each time, you learn more, and get better at ordering. At first, you don’t know if you need wide, medium, or narrow glasses. The most difficult part is calculating your the distance between your pupils. They have a default you can use, if you don’t know. A friend I tasked with measuring my pupillary distance with both a ruler and calipers, was unable to do so (gave up after giving me unrealistic, and different, numbers on 2 tries). I had to try to do it in the mirror—not recommended. My years-old prescription paper does not list my pupillary distance, unfortunately.
I became of the opinion that continuing to get stronger and stronger prescription, is a vicious cycle. I have proven that to myself. I could use a stronger prescription, but also my eyesight has not gotten any worse over the years. I actually feel like I didn’t need glasses when my parents forced me to start wearing them. And I believe my vision would be much better today, if I could have put off wearing glasses as long as I wanted to.
Years ago, Goggles4U had more ‘normal’ looking frames. The ones I have seen lately (haven’t visited in awhile, kind of gave up for this reason), are overly stylized (I think bizarre looking), and geared towards what they call “designer” frames. I am glad I got the two I did, when I could. Even those, are IMO a little overly retro or “hippie”, which style has been foisted on us for years, and still has not gone away.
When I saw how cheap some of the G4U stuff can be, I concluded that most of the cost of glasses from glasses stores, was not the product, but the overhead of keeping a building, employees, etc… I think the actual product is probably the smallest expense a glasses store has. One valuable service a glasses shop does provide, is setting the glasses up for you (nose pad alignment, ear curve). And of course being able to try different frames to see how they look and feel. But when I go into a glasses store, I don’t like any of the styles anyway. I prefer to buy things online anyway, but I’m unusual. And I cannot tell a difference in construction quality of G4U versus store frames.
Goggles4U has a number of options, including re-lensing your old glasses, though I would be hesitant to send any irreplaceable frames to them. I believe they will ship bare lenses (blanks) to you, like you asked. Another purpose for doing that would be snorkelers and SCUBA divers. There are diving masks where whole blanks can be fitted. I have seen them in dive shops years ago. I was shocked to see how California, USA effectively made prescription diving masks illegal, by forcing all lenses and glasses to be purchased from an ‘authorized’ eyeglass store. The California dive shops woud sell those dive masks, nor would they fit lenses for you, even if you had them. Outside of California, getting them not a problem. Seriously people, socialism is the devil. It was also illegal for dollar stores in CA to sell those cheap-but-good reading glasses for farsighted people. The optometrist industry also somehow got pinhole glasses nationally outlawed. Pinhole glasses work, no prescription needed, but all the ones I’ve seen, like on Ebay, the holes are too big, so they don’t work right. If they are truly the size of pinholes, they do work, and it is amazing. You get a glimpse of how much helpful products or technologies have been suppressed, because they were too simple, too inexpensive, and too effective.
The last time I got a lens prescription, I asked for a copy of it. Everyone should do this, just to have it. You might need it someday. In CA, they might refuse that, I’m not sure.
I have no affiliation with G4U, and again, wish they would re-expand their selection of lower-cost frames. They had a number of nice, more normal-looking, very inexpensive frames that sold out, which they unfortunately never re-stocked.
PS I really like the idea of cheap, custom prescription cycling glasses! Let us know how it goes—please!