You should consider three main points when choosing an eyeglass frame for your face shape, according to The Vision Council:
•Eyewear should repeat your personal best feature (such as a blue frame to match blue eyes).
•The frame shape should contrast with your face shape.
•The frame size should be in scale with your face size.
Also, while most faces are a combination of shapes and angles, there are seven basic face shapes: round, oval, oblong, base-down triangle, base-up triangle, diamond and square. Here is a further description of these face shapes and which types of frames work best for each, according to The Vision Council. A good optician can help you use these guidelines to choose your new eyeglasses.
A round face has curved lines with the width and length in the same proportions and no angles. To make a round face appear thinner and longer, try angular narrow eyeglass frames to lengthen the face, a clear bridge that widens theeyes, and frames that are wider than they are deep, such as a rectangular shape.
An oval face is considered to be the ideal shape because of its balanced proportions. To keep the oval's natural balance, look for eyeglass frames that are as wide as (or wider than) the broadest part of the face, or walnut-shaped frames that are not too deep or too narrow.
An oblong face is longer than it is wide and has a long straight cheek line and sometimes a longish nose. To make the face appear shorter and more balanced,try frames that have more depth than width, decorative or contrasting temples that add width to the face, or a low bridge to shorten the nose
A square face has a strong jaw line and a broad forehead, plus the width and length are in the same proportions. To make the square face look longer and soften the angles, try narrow frame styles, frames that have more width than depth, and narrow ovals.