bifocals
UK[ˌbaɪˈfəʊkl̩z]US[ˌbaɪˈfoʊkl̩z]
n
a pair of eyeglasses with lenses that have two different focal lengths, one for near vision and one for distance vision.
Morpheme Breakdown
bi
focals
bi
two
focals
lenses
Etymology
the word "bifocals" is a modern compound formed within english. its first element, "bi-", is a latin-derived prefix meaning "two," widely used in scientific and technical vocabulary. the second element, "focals," is a plural noun derived from "focal," which itself originates from the latin "focus," meaning hearth or fireplace—a central point that metaphorically evolved to denote a point where light rays converge. the term was coined in the late 19th century, attributed to its inventor benjamin franklin, to logically describe eyeglasses that ingeniously combine two distinct focal points within a single lens system for dual viewing purposes.
Analysis
Structure: bi (two) + focals (lenses)
- bi: from latin "bi-", meaning "two". a numerical prefix.
- focals: from the english word "focal", relating to a focus or point of concentration, derived from latin "focus" (hearth, fireplace). in this compound, it functions as a noun meaning "lenses".
Examples
he switched to bifocals to avoid constantly changing between his reading glasses and distance glasses.
the new progressive lenses offer a more seamless transition than traditional bifocals.
she peered over the top of her bifocals to get a better look at the distant sign.