Bifocals are special glasses designed for people who have trouble seeing both up close and far away. They have two different lens sections: the top part helps with distance vision, while the bottom part is for reading or other close-up tasks. This design allows wearers to switch between the two types of vision without needing to change glasses. Invented by Benjamin Franklin, bifocals are popular among older adults who often experience presbyopia, a common age-related vision change. By combining two prescriptions in one pair of glasses, bifocals provide convenience and comfort, making daily activities like reading, driving, and watching TV much easier.