AU where Scott has surgery when he’s a teenager, with the goal of this surgery being to give him control of his optic blasts. And the surgery works as intended, but only in one eye. Something goes wrong and the other eye has to be sewn shut. This naturally compromises Scott’s depth perception, and for Scott, depth perception is actually super important. Understanding the shapes of physical spaces is actually necessary for him to most effectively use his powers. If he judges space incorrectly, he can hurt people pretty badly. So you end up with a Scott who has been relieved of his primary burden — the fear that he could accidentally unleash the awesome power of his optic blasts, as Silver Age prose might put it — but also a Scott who is significantly less effective in combat. (Bonus points if the surgically installed eye controls are designed for regular life rather than combat and are therefore somewhat cumbersome in a fight.)
How this affects AU Scott probably depends on when the surgery happens. If it happens before Xavier forms the X-Men, then Scott probably doesn’t experience it as a downgrade. Scott’s not as effective as he could be in combat (or flying a plane), but he doesn’t really know that. Perhaps if he’s not quite so good at being a superhero and if he’s not constantly worried about his glasses coming off in public, then he bases his identity less around the X-Men. This can open up some more options for where he ends up and what he does and who he becomes.
But if the surgery happens after Scott’s been the field leader for the X-Men for a while, then it absolutely wrecks him psychologically. It’s the only thing he’s ever been good for and he’s not even good for that anymore. Also, he only wanted the surgery for selfish reasons (so he could live a more normal life and not worry about hurting others) and now all of his teammates are paying the price. :)
