Most people find direct sunlight much too bright and vibrant to be comfortable, moreso when reading off the paper in direct sunlight, especially on a bright day. During outside activities like biking, sledding and swimming, your eye can get more light than normal. It is advised to wear these kind of glasses when you are outside to keep your eyes safe from UV light, which can bring you cataracts.

Shades have also been closley linked with celebrities and movie actors mostly due to the want to hide who they are, but also because of the movie production lighting being so much more harsh than sunlight, makes their eyes sensitive to light.

But hey, the real reason people wear designer sunglasses is because they just look darn cool!