Who would poke any animal in the eye to test vision?? Eye caps or no, that's not even remotely scientific...
If I wanted to test her vision, I'd take an object of sorts and wiggle it around. Problem is that anything that is a different smell/temperature would ruin that experiment...
Perhaps a shadow test, first? If she sees movement and reacts, then it can be confirmed she is not 100% blind at least.
I'm not going to do this. Speaking theoretically.
Herp Derp