old kitty

Hello there, I adopted a cat 11 years ago, he was old then, they did not know his age. Right now, all he does is sleep eat and on occasion vomit. Is there a right or wrong in how I should let this continue, and YES I feel guilty for asking....I love him, and when he is on my tummy where he likes to be he is happy. But wow, does he have bad bad breath, one blue eye, (not the color, more like loss of pupil)...my husband wants me to have him put down, and I can't do this....I guess I am just confused, he isn't in pain or anything, just kinda old ....My guess is he is at least 20 years old. Any hopeful input? thanks... Tweet