Regarding glasses I find the most important thing to consider is your face shape,this is a good place to start if you’re stuck and unsure about your style of glasses.
Have a good look at yourself in the mirror also get familiar with common face shapes like oval,square or heart shape.
When this is sorted you will find it much easier to make your decision.
Oval shaped faces.
If you have an oval face you have a softly rounded forehead and chin, with has fairly balanced proportions.
Almost all frame shapes will suit you, you can be as flamboyant as you like. When choosing the style, size and colour of your new Glasses.
I would advise going for Frame that is a little wider than the widest part of your face.
Heart shaped faces.
When you have a heart-shaped face,it will be widest at the forehead, gently narrowing down towards the chin with soft features. To offset the natural wideness at the top half of your face, you should choose glass-frames that are a little wider than your forehead.
Round shaped faces.
Your face tends to be fairly short with a wider forehead. You have fuller cheeks and a more rounded chin and softer jawline.So I would advise that you choose styles that will enhance your softer features, so go for rounder frames for your glasses.