We have two old dogs - 14 and 15 years old. My old girl (15) has only partial hearing and her eyes are looking a bit cloudy. She can still see me from right down the other end of the yard though so I'm not too concerned at the moment. She is the most beautiful dog and I dread the day she goes. She does sleep alot, but she seems happy. Eats well, is able to get around quite well and still loves to play catch -although I limit it because I keep thinking she'll have a heart attack! I thought we were going to lose her 3 years ago when she became quite ill. The vet said things weren't looking good, but she came through it and has been fine ever since. I remember at the time just wishing and hoping for more time with her, even a few months.
Our other dog (male, 14) still thinks he's a puppy and runs around like a lunatic! I keep thinking he has to slow down sooner or later.

We will have both dogs cremated, because I don't ever want to leave the behind if we move. We've had them since we were 18/19 when DH and I first moved in together.