Eyes/Non-crusty blind?

Hi, I am kind of new here. I have been a cavy owner for about 6 1/2 years. I used to be a member of cavy cages but hadn't posted in some time and had to re-join. My only guinea pig , is currently almost 6 years old. I noticed last week that her right eye looked sorta whitish. Over the past 6 months or so it was sort of cloudy, but kind of like how an older person's eye looks when they get cataracts or glaucoma, I think. But last week or so it looks almost blind. She spends most of her time in her igloo so I don't see her out too much. She has never really liked being held, so try not to stress her out too much by doing that often. Yesterday when I cleaned her cage, I noticed her eye is definately even more white than before. Her other eye is normal. I think she may definately be blind in that eye. It looks like when a dog or horse is blind in an eye. She also acts sort of disoriented when I have to move her igloo to clean, and she can't see on that side when she moves around. She is definately more comfortable staying in her igloo. She is still eating fine. Although it seems she might not be drinking "as " much. I may need to move her hut closer to her water bottle so she doesn't have as far to go.
I was wondering if anyone else has had a piggy go blind in old age? Is there anything else I should do for her comfort? What causes this, just age I guess?