Doe Blind in One Eye

[Lanthanum]

My Bonnie, ever since I got her, has had a white hazy pocket on top of her left eye. She doesn't seem to be bothered by it, but it's obvious she can't see much out of it. When at the vet for her ultra sound, Dr. Gibson said he doesn't know what it is but she definitely can't see out of the places the pocket covers. Any ideas on what it could be? It doesn't hurt her I'm just curious since even the vet didn't know what it was. The best picture where you can see it is this one

 

[norseofcourse]

Maybe an old injury? How old is she?

 

[Lanthanum]

Maybe an old injury? How old is she?

She's four years old, I got her when she was about 8 months. She didn't have that when I got her, but she never showed signs of injury. It just showed up slowly without an obvious cause