biconvex lens n.
A lens with both surfaces convex. Also called convexo-convex lens.
Where two toes overlap, it will be observed that there is a deeper shadow, like the section of a biconvex lens.
The ovum now assumes somewhat the form of a biconvex lens, in the axis of which the central perforation is still present.
Disk a rather flattened, biconvex lens, about twice as broad as thick.