For me wearing eyeglasses is not purely just about function and practicality but an opportunity to express myself. I view eyewear as another accessory in my arsenal to use to complete my look. I've worn glasses since I was an adolescent and I didn't always like the styles that I selected but I knew I
wanted multiple pairs.
Having only one or two pairs is boring and predictable. I think that as varied as the seasons, your mood, your wardrobe, your occasions, and your shoe collection you should have an eyewear collection that is just as extensive. This should include prescription (for those who need them), non-prescription (for those non-eyeglasses wearers who want to change up their look), and sunglasses in a variety of styles and colors that can complement your look and add a bit of confidence to your overall appearance.
Personally, I'm a big fan of Warby Parker (www.warbyparker.com) given the price point, service and selection. I also like higher end designers and brands as well. Price shouldn't necessarily be the major driver of whether you buy a particular pair or not, I suggest focusing on what looks best on you and what message you are trying to convey (am I feeling adventurous, artistic, serious, or carefree today?), the occasion you'll likely wear them, and the audience who'll observe you in your eyewear.
There are some that suggest you find eyewear that complements your facial structure. I'm less inclined to follow this approach as you may end up highlighting a feature for which didn't intend, ha! Instead, spend some time going to different eyewear boutiques and try on as many pairs as you can to truly get a good sense of what works for you. You may want to bring along someone whose opinion you trust. Warby Parker makes testing out glasses easy by sending you up to 5 pairs to try on at home for 5 days--for free! Stay stylish friends.