Ive never heard of having a prairie dog as a pet, but Ill tell you this.... My dog had that same thing for about a week. After a few days we took her to the vet and they tested her for everything they could think it might be. They had no conclusion but after about a week it went away. She did have trouble seeing, she would walk in to things and fall down the stairs. But everything turned out alright.
My prairie dog just developed the same thing. He's about 10, and I think it may have been developing for a couple months. I started seeing what looked like cloudiness in his eyes, but thought it was just reflections of the light. Last night I saw his pupils are almost completely white...it really freaked me out. Did you find out what was causing it with your PD's?
Sometimes cloudiness in the eye can be a result of an injury or infection. Or it could be cataracts. Yes, other animals can get cataracts too. We had a first year vulture come in with cataracts. Never knew the cause but there it was, a very young bird nearly blind.
A vet can take a look at the eyes, try some treatments and see if they clear up.
I don't know much about prairie dogs (minus that they are the largest pest out here in alberta with all the farm land - I won't tell you the things farmers do to them). I just recently got a couple of degus (another rodent) and through research found out they cannot metabolise sugar at all. When they are fed sugar on a regular basis (as 90% of food for them - chinchilla food has sugar in it) they develop diabetes and one of first symptoms is cataracts and white eyes. It would worth checking into whether prairie dogs are similar.