Oval
Pretty much any style works on an oval face. You can experiment with the latest looks such as the retro wayfarer and the cat-eye as these shape will accentuate your cheekbones. Detailed arms will add definition whilst metal framework will soften your face shape if you prefer a more subtle, everyday style. The golden rule is to choose frames that are wider than the most widest part of the face.
Round
With such a soft shape, definition is key so slim your cheeks with a frame slightly wider than the broadest part of your face. Soft but angular styles will pull your temple higher, lengthening your face and breaking up the roundness. Stay away from round frames and opt for solid square and rectangular frames instead. Embellished arms will accent a frame, giving a round face more definition.
Oblong
To balance out your face and give it width, choose glasses that don't extend beyond the widest part of your head. Opt for round, oval or square shapes but keep away from anything too angular that might jut out at the edge. Aviators and oversized frames will accentuate cheekbones and chisel your features. Decorated temples draws eyes outward thereby making the face seem wider.
Square
A strong jaw line with wide cheekbones looks great with rounded or aviator-shaped frames. With such a strongly shaped face, oversized and curvy styles also work well, while creams and neutral tones help to soften and subtly frame the face. Stay away from too much detail on the outer edges and arms. Opt for frames that are narrow and wider than they are long.
Heart
A defined, pointed chin with wide cheek bones and forehead look great with quirky, retro shaped glasses, such as the rectangular or 'cat-eyed' styles. Choose a pair which angle outwards towards to top corner, widening out the face to balance the jaw line. Coloured frames and arms with strong detail will soften the lower portion of your face shape by accentuating the eye area.
Diamond
Diamond shaped faces are narrow at the eye line and jawline, and cheekbones are often high and dramatic. To highlight your eyes and bring out the cheekbones, try frames which have detailing or distinctive brow lines. Rimless, oval and cat-eye shapes will balance out a diamond shaped face. The wayfarer is a great unisex style which works in perfect synergy with small features.