Come and work your magic MNetters!
Sci-Fi genre book. I read it early 00s along the same time as I read Michael Marshall Smith.
It's an odd book. About some ex army guys (I think) who had previously been sent in to a different reality. To do this they had to have special chip put in their eyes because the light was different in there. I vaguely remember them being hunted by a sort of tiger. The place sent people a bit crazy and one particularly disturbing part recounted one of the guys slitting the natives throats and fucking the slit.
I think I'm conflating 2 books here, but the other thing I remember is that to get in the reality they had a guy fly a plane over the sea until the sea looked like sand and then they walked on it and got in to 'jeem land', named after how a kid say dream.
Good luck 🤣 and thanks. It's driving me crazy!