I read the book mid to late 90s and it seemed a bit old then so could have been published late 70s or 80s as well as 90s. My guess would be mid to late 80s.
The title was something unusual and not easy to remember. Some kinda fantasy or sci-fi type words involved.
The cover was bright with vivid colors. If I saw the same cover again I would know it in a second. I think there was a cat or two in the foreground and at the top was a bright object, either a colorful sun or a square ship in the colors of a sunset.
The main characters are all cats, I can't remember if there were humans in the story at all, if they were they weren't very important. It was about house cats not big cats and they may have had humans but it was about the cats interactions and their philosophy.
The cats believed the sun was the eye of their God. And when the other sleeping eye opened the world would end. The story was about preventing that end of the world most likely. There may have been alternate universes or other planets involved.