Try the frames, look into the mirror and purchase the pair that looks best on you. The bridge length, frame angle and the rim width of the glass should match with your face. Square and rectangular frames suit almost every type of face. You can analyze it from different angles after wearing the frames.
If you have mistakenly purchased such a type of frame, then you need to hide the under eye shadows with a concealer. Usually the corners of the eyes appear a little darker than the rest of your face.
Observe the difference after wearing the glass and apply the makeup accordingly. Outline your eyes with a kohl or an eye liner and add appropriate eye makeup. The sparkle in your eyes adds elegance to your personality. Also, add proper makeup to your jawlines and forehead. All these beauty effects get further superimposed by your glass.
This was all on how to look pretty in glasses. Remember all these points when you step inside a showroom displaying numerous glasses. Although fashion remains your priority, do not get swayed away by it. Try the eyewear repeatedly and make sure you are comfortable in it. Lastly, you look pretty only when you have confidence and grace in your personality.