Multifocals are the glasses or contact lenses themselves — the things you wear. “She has started wearing multifocals.” The adjective is multifocal; this noun is almost always plural, like glasses, scissors, or binoculars. People do not often say “a multifocal” for one pair, though you might hear “a pair of multifocals.” They help you see things that are near and things that are far, in one pair. In an English-speaking shop, patients still say bifocals for the old lined kind and multifocals for the newer many-focus or progressive kind — and again, not everyone is careful. The word is at home in the clinic and the optician’s, not in casual chat unless someone is talking about their eyes.

多焦眼鏡、多焦隱形眼鏡（店裡常說「漸進鏡」）