noun
convex lens
A lens that is thicker at the center than at the edges, used to converge light. Common in physics and optics contexts.
凸レンズは光を一点に集める。
A convex lens focuses light to a single point.
虫眼鏡には凸レンズが使われている。
A magnifying glass uses a convex lens.
Concave lens, which is thinner at the center and diverges light, opposite of 凸レンズ.
Compound of 凸 (とつ, 'convex') and レンズ (from English 'lens').