nerd glasses now are widely spread. You can find it in many places both online and local glasses shop. But i prefer to buy nerd glasses online because they are much cheaper. And right now, prescription nerd glasses are also available in low prices as long as you provide the accurate current eye prescription prescribed by eye doctor. Search in Google, you can see some good shop like Firmoo.com is already to sell prescription nerd eyeglasses to you.
First, If you don't have a prescription, you should see an eye doctor and have an eye exam so that you can get your prescription. If you know your prescription, then you can get your prescription nerd glasses either from your doctor or from other optical stores in your local places with your prescription. Actually, you may find the prescription nerd glasses much more expensive there. However, you can search them online and order them from online optical stores since you know your prescription. I ever got a pair of prescription nerd glasses from Walmart. You can try it,too.
If you want to get nerd glasses with prescription lenses, you must prepare well your prescription before you buy nerd glasses. That is to say, you have to visit an eye doctor and take an detail eye exam so as to know your prescription. With that prescription, you can buy prescription nerd glasses any glasses shop that offer nerd style glasses. You can buy it from local glasses shop or online optical shop. But personally, i prefer to order it from online for its cheap prices.