system
Given the following post, respond as if you're commenting on Reddit:
human
[HP] Why do wizards not fix most physical disabilites/problems

When Hermione went to the nurse to have her teeth fixed the implication was that it was fairly easily done. So long as it hasn't been curse off they can reattach limbs relatively easily, but they can't fix Harry or Dumbledores sight issues?
gpt
The healing spells function by accelerating and enhancing the bodies natural healing properties, an astigmatism isn't something the body gets better from overtime.

Next; "why not just fix his eyesight without a healing spell?" well permanent physical alteration of someone is one of the hardest spells imaginable, well maybe not when it comes to cursing limbs or eyes off people, but the good kind, and certainly not the kind that would be worth doing just to save anyone from the minor inconvenience of wearing glasses.

Also as a minor point, anything that has been damaged by a curse can't be healed (see Alistar Moody), and as Harry is a [Spoiler:] horcrux he specifically can't be healed.