There's a Woody Guthrie song called Tom Joad, about the Grapes of Wrath character. One of the lines is "everybody might be just one big soul, well it looks thata way to me". This is always what I think about when I look into the eyes of a pet, especially a dog. I can see the soul of all my former companions when i look into any random dogs eyes...and get teary eyed. Maybe it doesn't make sense but I'm thinking you can see Heddy again one day through the eyes of another cat.
Sorry for your loss