Concave Lens
/ˌkɒnˈkeɪv ˈlenz/noun
A lens that is thinner at the center than at the edges and causes parallel light rays to diverge.
Did you know?The word “lens” comes from the Latin word for lentil because early observers thought the curved glass resembled the legume’s shape.
Etymological Timeline
Proto-Indo-European
PIE
*keu-
“To swell, hollow, or be curved; a proposed ancestral root connected with cavity words.”
Classical Latin
Latin
cavus
“Hollow, concave, or sunken inward.”
Classical Latin
Latin
concavus
“Hollowed or curved inward; concave.”
Classical Latin
Latin
lens
“Lentil; later, a lens because of its lentil-like curved shape.”
15th Century
English
concave
“Hollowed or curved inward.”
17th Century
English
lens
“A piece of transparent material shaped to refract light.”
Modern English
English
concave lens
“A lens thinner in the middle that spreads or diverges light rays.”