Convex on both edges as a biconvex lens
- convex on both edges; shaped like a lentil
- Convex on both edges; since, a biconvex lens.
(a.) Convex on both sides; as, a biconvex lens.
In the first it is a biconvex lens, from which segments are continually cut off parallel to the posterior surface; and in the second an elongated dome, from which segments are cut off by a transverse wall.