...Of course, thematically "Space Seed" could
use a scene or two where the inferiority of Kirk's genes is highlighted. So what if he's nearsighted - he can still defeat a physically superior specimen with his hands tied behind his back, because, well, he's the good guy and fights with a pure heart! (Unless that's genetically inferior, too, and has been replaced by a machine... But apparently that scene was among the ones cut, and had to wait for two decades to see use.
But even then, it would be odd that Kirk would have to receive tutoring on the use of glasses. Perhaps in an ideal world, "Space Seed" would have launched a story arc of sorts where Kirk's age gradually begins to show, Shatner ceases to wear the wig, etc...