Explanation:

- People who wear bifocal lenses have:

- Presbyopia: Correct answer. Bifocals are designed for presbyopia, a condition common with aging where the eye gradually loses the ability to focus on nearby objects.

- Hypermetropia: Also known as farsightedness; corrected with converging lenses, not bifocals.

- Myopia: Also known as nearsightedness; corrected with diverging lenses, not bifocals.

- Cataract: A clouding of the eye's lens, typically treated with surgery, not lenses.