Here is an excerpt from an article that I found on the Internet:
The Sun gives out light, but it also gives out heat energy. This heat energy is focused and concentrated onto the central part of your retina, which deals with fine vision. If you stare at the Sun for long enough, you will burn out that central part of the retina. Your peripheral vision will be fine, so you’ll still notice something approaching from the corner of your eye. But if you try to read any fine print, it’ll be fuzzy, as if you were looking through a metre of seawater, or a glass smeared with petroleum jelly.
I personally don’t know anyone that was ever blinded by staring at the sun.