Do you look at the sun through the camera's viewfinder? Not a good idea. Better to use your camera's LCD screen.

If you do look at the sun through your camera's viewfinder, you might get something called solar retinitis or solar retinopathy - explained by:
Michael M. Cohen, OD, FAAO
Eyecare-Media Consulting, LLC
1401 Via Loma
Walnut Creek, CA 94598-2926

The problem is that it is cumulative throughout life. A small does here and a small dose there lead to the condition.

If someone says, "I looked at the sun through my viewfinder and nothing happened," that's not true.

I've treated hundreds of people with this condition. I tell my patients that there is no real treatment other than prevention.

Photographers needs to protect their eyes, and hence their vision, throughout their life.

For more info, check out this link:

http://en.wikipedia.org/wiki/Solar_retinopathy

Solor Retintis may be reversible in some cases, but sometimes it's not. Your mileage may vary.