ZenniOptical. My prescription is pretty strong (-6) but they manage to make the lenses pretty thin. I think a usual pair costs me $50 versus $500 at the optician’s store.

Bought a couple of pairs from Costco.

Zenni has really good prices. I bought some prescription sunglasses from them for about $50. The site suggested I spend an extra $70 on high-index lenses but I ignored it. Glasses work great.

My last ones are from Zenni. No complaints.

In fairness, my optometrist has reasonable prices and good selection. And I’ve had good luck at Walmart in the past.

I know people who have good luck shopping online because of the price and variety, but I prefer in person because I'm so incredibly picky about my glasses.

Either Zenni or EyeBuyDirect.

Bought a pair from Zenni some 3 years ago for literally pennies (15$ for the frames, 10 for lenses). I have since carelessly snapped them (but keep elongating their lifespan unnaturally with super glue). Gonna buy my next pair from Zenni. I swear by them now for how cheap and durable these are, rarely had a pair of glasses survive 2 years before, and these were so much cheaper.

They also have regular people levels of quality, but I'm poor so it's nice they have shit for people like me too.

A bit pricier than the other options listed in this thread but I'm really happy with my glasses from warby Parker. I like having an in person store to try on frames and the customer service is pretty great

Zenni is pretty good. My current pair is from Firmoo and is also pretty good. Goggles4u has also worked fine for me, but they took ages to ship.

Eye Buy Direct was half the cost of even the cheapest store bought glasses in our case, and I really like their order status tracking! Don't sign up for their emails though, you'll get like five a day 😳

Depending on how picky you are about how glasses frames might look or feel, you may want to consider finding frames separately and mailing them in to get lenses added. It will still save you money! But if you're less picky they do have both virtual try one and measure your pupil distance so your chances of liking them seem good!

EyeBuyDirect and Firmoo.

Bought my current pair from Zenni. Getting the pupilary distance was a bit of a pain, but I've been happy with them. And the price was much better than the wallet rape by Luxottica.

I've been buying from Zenni for the past few years. You can't beat the prices for prescription glasses.

I've been going with EyeBuyDirect the last few times I've gotten new glasses. I've used Zenni a few times, and they're definitely on the list of places I check, but EBD has a better selection. I save so much money on frames I can afford better lenses, and they run 2 for 1 deals pretty often. So I get a pair of regulars and a pair of polarized sunglasses.

You can upload a picture and then try on the glasses virtually and judge that way.

Had amazing luck with Warby Parker. Way cheaper than Walmart out of pocket for much, much higher quality than any of the vision stores I’ve been to

Eyebuydirect.

Online you have to know sizes and what not, you can get a vague idea what it will look like on you, they let you use your phone camera or webcam to get a better idea. But you can't beat the prices, glasses in the US are ridiculously priced.

Zenni, until I learned the V.A. makes glasses.

Zenni their prescription sunglasses are really good

For frames, check out the brand Silhouette. They’re so lightweight you can’t feel them.

Zenni as well here. Overall I'm happy. To answer your question: the website has a semi-functional "virtual try-on" that works well enough for checking the look of glasses. I only used to it gauge the size of them, because I have a big head.

Worth noting that if you have a strong prescription, you're going to pay more wherever you buy them. I have a -4.5 cyl number, and the glasses I wear now cost around $100, despite the frames starting at like $25

I use EyeBuyDirect. The only thing I don't like about them is that it's kinda hard to get a refund from them

Zenni Optical. I get progressive lenses with anti-reflective coating and a nice frame for a little more than $60 US. That's probably ten percent of what I'd pay at a mall store.

Online. Some vendors are crazy cheap

Walmart

Do reading glasses count? I just buy mine at the pharmacy.

I've bought countless pairs from Zenni for more than a decade and they've always been pretty good. Sometimes some frames might feel a little cheap but that seems to have gotten better. For kicks I just bought a pair from EyeBuyDirect and was very pleased. They had them to me in about a week and they are perfect. For the prices, especially for single vision, you could try with very little risk. One thing that I'd note is make sure you get your Pupil Distance measured accurately. I've tried at home and was off. Any doc will do it at an exam.