How does a cataract affect vision?

Initially the cataract changes the focusing power of the eye, and a change of glasses can satisfactorily improve vision. Gradually, clarity drops so that visual tasks become increasingly difficult, despite the best possible glasses.
	A person with cataract views the world as if through a dirty window or a windshield that needs defrosting. Glare becomes a serious problem. Color perception becomes muted.
Reading, driving, computer work, hobbies, and athletics become less easy and eventually impossible due to diminished vision.