Nerd glasses are very popular now and many people want to wear nerd glasses. Those people who have vision problems need to wear prescription nerd glasses. I've noticed that many optical stores have nerd glasses sold either in the real store or online optical store. You can go to see an eye doctor to have an eye exam first. Then you select the type of nerd glasses frame and the type of lens material. The doctor will make you prescription nerd glasses. However, they will cost you too much if you get them from your doctor. You can get cheap prescription nerd glasses from online optical stores, like walmart.
With the popular of nerdy style glasses, there are many shops sell nerd glasses & frames. You can find prescription nerd glasses in local glasses shops or online. Considering cheap nerd glasses, you can go online such foreyes, walmart, or 20/20 etc. Or you can order prescription nerd eyeglasses from some special online optical shops like Firmoo.com, Framesdirect.com etc. And i also heard that firmoo offers free glasses. You can have a look, Good lucky.