From this interesting question and with its even more interesting answers, I deduce following:
- Poor eyesight cannot be healed by even Magic
- Harry had already been in trouble numerous times due to his poor eyesight.
Update: From comments, here are few incidents of movie/book:
- In PoA, the Whomping Willow broke Harry's glasses
- When Harry uses Floo Powder in CoS, his glass breaks.
- Hermione places a charm on Harry's glasses in PoA to repel the rain during Quidditch.
- Snape threw Harry so hard onto the dungeon floor that his glasses fell off out of the tent...
There are many more instances also (not able to recall).
So my question goes here: keeping the diverse literature of Harry Potter in context, would there any major or minor impacts in plot, or story altogether if Harry didn't wear glasses?