It can be hard to test pets' sight, but there are several things you can try.
The menace reflex tests that the animal can see and blink. if your cat can blink, then if she doesn't respond to the menace test she might not be able to see.
Fig 20.16, page 554, here:
http://books.google.co.uk/books?id=NOoK2shM5NI C&pg=PA554&lpg=PA554&dq=menace+reflex&source=w eb&ots=IMcjigRxfp&sig=8gHL4rU10BXsybzvj565CEqu _Zc&hl=en
You could also try the thing with the cotton ball. Covering one eye and dropping a cotton ball in front your your cat, you'll be able to see if she sees it or not.
Same page, Fig 20.17.
However if she can see at all, i.e. if she can see through her right eye, she shouldn't be bumping into things.