U know that eyes are very delicate part of our body. They r damaged by UV radiations which coming from the sun, whether it is overcast & sunny day. Sunglasses should be warn in daylight period when U r outside & U need to be sure that the sunglasses you choose offer UV rays protection. There r many sunglasses sold which are not really protect our eyes. Plz, Check the label on your sunglasses before you buy them & be sure to wear them.