I went to the vets, not all the eye is completely covered with the cataracts, but she is still more or less totally blind. If looking head-on they look all over, but if you look from the side you can see little bits of black around the edges. The vet was young and a bit inexperienced I thought possibly, she took a blood sample for diabetes and that was fine. She gave her some antibiotics and anti inflammatory injections and myself some tablets. I have to go back in 2 days to see if she has improved, if not they will take some blood for further testing of kidney and liver functions. My other cat died of kidney failure this time last year, but lived with it for around 3 years after diagnosis. She has actually been eating a bit more today and walking about more which is a good sign. Thanks for the replies, and sorry to hear about other peoples pet issues.