Wee cat is approx 15. We rehomed her from the sspca at roughly 2-3 years olds and she had been a joy.
She developed hypothyroidism which we treated by a month stay at the Royal vet school for radioiodine therapy. She then showed symptoms of idiopathic feline cystitis which we treat/manage by cystophan supplements and feliway plug ins around the house (as well as no dry food, multiple litter trays cleaned every day and fresh water in bowls around the house).
Now we think she is blind 
Initially we thought it was only in low light as we gently shone torches towards her and she seemed to react. But now I suspect she is completely blind. She has walked into my legs numerous times today both in broad daylight and in Lowe light.
Does anyone have suggestions on how to make her life more comfortable? We have a 3 year old who adores her 'sister' but is is hard managing their interactions given how much old cat seems to come and go.
Not sure what I am asking. Happy endings anyone?