Ok, i can see that you just want to know why the man, howard stern , who is a famous American celebrity, always wears sunglasses during his show in public. Anyway, you should know those famous personages just want to appear more attractive and mysterious, and some of them are really ugly so sunglasses could cover their weakness. Also, wearing sunglasses on a regular basis might just be an individual habit, so it is quite normal. Of course some awesome sunglasses could make them cool.
I also noticed that howard stern wears the sunglasses too. I think it is just for the cool looks. As we know, the sunglasses are always used to protect the eyes from the uv rays and other bad lights. Actually more and more people now tend to wear the sunglasses just for the cool looks. They regard it as the fashionable accessories.