So what? Why does it matter what Darwin did? Darwin is not a god of evolution. You are appearing to project your religion upon others.
Once again, science advances over the years. When Darwin got things wrong, and he did, or many of the things that Darwin did not know, were corrected or learned since his time.
Every time you try to say "but Darwin . . ." the proper answer is almost always "So what?"
The founder of the theory of evolution gave doubts to natural selection to the degree of not having another opinion. This isn't about my beliefs this is about Darwin believing that evolution is a theory. Did science create an alternative theory for what Darwin couldn't explain or didn't know about the eye?