I have an elderly Corn that has the equivalent of cataracts and seems pretty much blind. He finds his food without problems, because he uses heat sensing to pick up where the food is in the feeding tank. Next time you offer a mouse, make sure it's really hot - hopefully that should help yours locate it.
I do have the problem where mine has trouble distinguishing between a hot defrosted mouse (edible) and my hand (inedible - but only once he's had a speculative chew on it first!), so I wear gloves. They block the heat from my hands and so that he doesn't get the two mixed up.
I don't think there's any way to be absolutely sure that a Corn is blind, because they use sight, heat and vibration to sense movement. If they lose one sense then they just swap to the others. However, mine lives a good life and appears to behave normally. I've also known someone who runs a snake rescue and has taken in blind Corns over the years. She's not had any specific problems with their general behaviour. Her observation is that these tended to be lighter coloured morphs, lacking black pigment, that had been kept with UV light (not actually necessary for a Corn). It was her view that the concentrated UV damaged their eyes in some way, although I don't believe there's ever been a formal study on the subject.
Hopefully if that's the problem with yours, then she'll be fine despite it. You'll just have to watch your fingers!