You really need to take her to the vets. They will be able to perform a detailed examination of the eye.

Dogs do lose their sight with age, but 9 seems a little young. Collies do have a hereditary eye problem..

CollieEye.org.uk - Collie Eye Anomaly information resource

__________________

I am just a worthless liar.
I am just an imbecile.
I will only complicate you.
Trust in me and fall as well.
I will find a center in you.
I will chew it up and leave,
I will work to elevate you
just enough to bring you down