There is a common misconception that any eye problem can be fixed by wearing the proper glasses. This, unfortunately, is not true. Glasses and contact lenses help correct eye problems related to focus, and that's it.
Think of the eye as a camera. If the camera is out of focus, then it won't take a good picture. Focus the camera (or wear glasses, in our analogy), and you'll have a clear image.
Extending the analogy, here are a few categories of eye problems that cannot be fixed by wearing glasses:
Cataract (lens smudged)
Corneal disease (cloudy screen)
Optic nerve disease (dead battery)
Retinal disease (bad film)