The best glasses for each face shape generally balance out the heavier features of that shape, so people with round faces may look better in narrow, angular frames, while people with square faces often look better with curved frames. People with oval faces can usually wear any frames.
Face shapes are determined by comparing the width of the forehead, cheekbones and jawline, as well as the length of the face and the general shape of the features. A round face generally has soft, curved features and cheekbones that are wider than the forehead or jaw, while a square face has strong lines and features of approximately equal length. Heart-shaped faces have wide foreheads with narrower cheeks and chins, and oval faces are long with narrower foreheads and chins.
Heart-shaped faces often look best with rounded frames that have heavy or flared bottom edges. This helps balance out the wider forehead while drawing the eye to the lower part of the face. Diamond-shaped faces, which feature wide cheekbones and a narrow forehead and chin, may look best with rimless or oval-shaped glasses. Oblong faces, which are similar to square faces but are longer in length, look good in a variety of frames, especially those with sharp angles and bold shapes. For sunglasses, oversized styles may look particularly flattering.