If we needed to stare at the sun to thrive/survive, then it might be an issue. As it is, we reflexiely turn away and carry on.
It just seems logical to me that our eyes should be immune to the over exposure of light. Go with me on this for a second.
Natural Selection uses random mutations to refine and eventually change species. Amazing things have come from that process which involves a random element. The sun was there before the first single celled organism, right? Why aren't we sun people?
-Sab