Is Prudence Blind?

I think Prudence might be blind or at least has very bad eyesight. How this has escaped my notice for nearly three years I have no idea. Maybe she hasn't been like this the entire time I've had her, or maybe she just manages living with it very well.

Tonight I was holding her and petting her like normal. But tonight I noticed that when my hand gets close to her eyes, she doesn't blink. So I took my finger and moved it closer and closer to her eye. I got less than a centimeter away from her eyeball and she still didn't blink. I held her up to a light and her eyes remained fully dilated. My mom shone a very bright light in her face and her eyes did dilate some. So, she at least has light/dark vision.

I've never noticed her running into anything, but the layout in her cage is nearly always the same. When she's in an unfamiliar area, she moves slow, never runs. I tested this tonight too. I put her on the floor in a strange room and tried to get her to run, but she just walked very slowly, sniffing and wiggling her whiskers.

I'm trying to figure out if she really is blind or has bad eyesight. Pam also let me put my finger extremely close to her eye without blinking. So, maybe that's just a pig thing. If she is blind/nearly blind, it may be the reason why she refuses to go on the upstairs of the guinea pig cage, even when the only food is there. I will have to keep a close eye on her and see if she does anything that indicates that she has poor vision.