I have been looking for a particular fic for a while now but I have limited memory of the rest of the story, but there was this one scene that always stuck in my mind.
There was a part where the avengers/shield attacked an enemy's base and they find some human experiment where the villains were trying to replicate Clint's vision. I believe the victim died but Clint was feeling guilty about the whole thing and how the person suffered because of him.
If anyone recalls this story, it would be greatly appreciated if you can share!
FOUND! Thanks to laylee for finding Relief by Infiniteeight.