system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why are we told to exercise damaged muscles to restore normal function, but wear glasses for our eyes?
gpt
If one leg is longer than the other you're not told to fix it with exercise.  Vision problems are most often caused by eye geometry problems.  There are tiny muscles that control focus, and they are the strongest muscles in the body by mass, but workouts for them won't change the geometry that put your retina too far back into your head or chemical changes that make the focus lens less elastic.