If you would read my reply, I noted that they discoloration of the eye is a result of an eye infection, the eye infection is not killing the fish at this time. The condition of he stream could be killing the fish, if it was as warm as you say.troutdoorsman said:It was sitting in 2in of water up along the side of the bank. I picked it up with my bare hands. I don't know as much about bacterial eye infections in trout as you do, but I am sure that this trout died very soon after I left it. I measured the water temperature there and it was 74 degrees at 11:30am. This was last august. There are always substantial die offs on this stream during the late summer months.
I am not sure what about that situation would lead you to believe that rainbow will survive. Don't you think that maybe a cold water species living in luke warm water might not be as healthy as it could be, and maybe have a depressed immune system and become more susceptible to infection and premature death?