My wife has suffered from 3 detached retinas. She had weird vision issues, she described it as a ceiling on her vision in her eyes. We set up an eye doctor appointment, and he laser attached them within 3 days. Her right eye detached a second time, so when she went back he reattached the retina and filled the eye with a medical grade silicone. Her eye is legally blind, but it won't lose color in the iris, at least according to the doctor. She can see light, color, and perceive some movement, but can't see any images with it. He will likely not return full vision to the eye, but he might save some of it, if he seeks treatment.
It is not your fault, you did what you could. Let him know he can still save some vision, but it won't ever fully return, but only if he acts soon.