What do bifocal lenses typically correct?

Bifocal lenses are specifically designed to assist individuals who have presbyopia, a condition that typically occurs with aging, causing difficulty in focusing on close-up objects. These lenses contain two distinct optical prescriptions: one for distance vision and another for near vision. This design allows individuals to see clearly at both far and close ranges without switching glasses.

The presence of these two different focal lengths in bifocal lenses directly addresses the challenge of needing correction for both near and far vision simultaneously, making option C the most accurate choice. Other options single out specific conditions, such as only correcting for astigmatism, myopia, or color blindness, which bifocals do not address, as bifocal lenses are not designed to provide treatment for just one type of vision problem or color vision deficiency.