Cat eye frame are with rounded-out edges that work wonders for a square face or diamond shaped face. A round face can benefit from sharper edges, or large frames that curve upwards subtly. All that said though, the rules are never hard and fast: the best option is always to try, try, try on pairs until you work out what is right for your face shape and hairstyle. Get the right pair of 50s-inspired glasses or sunglasses and you will find they can work with many an outfit, from the very modern to the utterly vintage. If you are going for a vintage inspired look, stick to anything from the 40s through to the 60s. While 70s fashion is also seeing a major comeback, it is an era best suited to round frames. If you want to make a strong statement, try a pair of cat-eye or harlequin glasses with diamond-shaped lenses that point sharply out. For an everyday pair pair that will last, keep low-key and subtle with a slight flare out at the edges. Sources: http://www.fashionising.com/trends/b--cat-eye-glasses-sunglasses-4924.html
Generally speaking, cat eye frame glasses with rounded-out edges can look good on you if you have a square face or diamond shaped face. If you have a round face, you can large frames with sharper edges that curve upwards subtly. However, the best way is go to an optical store to try different pairs on until you find the right type for your face shape. Some people do look cool with the cat eye glasses.
I don't like the cat eye glasses, because it does not fit for my style. I think they are good for all fashionable youth no matter what their face shapes are. You can search on the internet to find some images that wear a pair of cat style eyeglasses with a square face. I think it looks really good on them.