Zenni is the main online company in the US selling eyeglasses for actually reasonably prices. Downside is that you don't get to try them on before you buy them, and I'm not a huge fan of their styles.
Zenni is great for frames. But if your eyesight is seriously bad (ie, -10 diopter) you're much better off getting lenses put into Zenni frames at a local optometrist. Zenni doesn't do things like lens edge bevel which becomes necessary once your eyeglasses are 1cm+ thick at the edges.
And no, high index of refraction lenses like Zenni pushes just makes things worse. High index lenses all have very low abbe number and their chromatic abberation is so bad at high diopter that I can even read the license plates of cars in the lane next to me while wearing them. They're only good for vision straight ahead.
In India there is Lenskart, who even have physical stores where you can try out frames, and then they ship the glasses to you. Last time I tried I got two numbers of specs, with the top of the line optics available with them for something like 65$.
And no, high index of refraction lenses like Zenni pushes just makes things worse. High index lenses all have very low abbe number and their chromatic abberation is so bad at high diopter that I can even read the license plates of cars in the lane next to me while wearing them. They're only good for vision straight ahead.