This is some general tips, which should on consider in mind while selecting sunglasses.
Before buying a sunglasses you should not look at the cost as good sunglasses will cost higher only . after that you should always look for 100% UV protected sunglasses, as it protects your eyes from the harmful UV rays, which can also lead to Cataracts. One should select sunglasses of bigger size as more will be the size, more will be the protection. Colour doesn’t matter in sunglasses as the main thing is UV protection, may it be black, green, red, blue but UV protection will be same. you should also look that it suits your face also.
So these are some general tips to be taken in mind while buying sunglasses.