Depending on the case, cataract evolves fast or slowly. Usually cataract affects both eyes, but one eye may become affected after the other.

When cataract becomes worse, everything becomes blurred. Reading and recognizing objects or people from a distance become more difficult and eventually completely impossible.
Sometimes it becomes difficult to see with a blazing sun or in the dusk, and people have a double image, a shining or a rainbow around light spots.

In the first stage of cataract reading sometimes becomes easier, but "farsightedness" seems to weaken.
Patients suffering from cataract seem to be looking through frosted glass or through a fall. "Cataract" is indeed the old Greek word for "fall".