adjective. convex on both sides; shaped like a lentil.
1. Adjective Magnifying glasses and microscopes work in the same basic way, using biconvex lenses (lenses with two convex sides) to produce a magnified version of the images. 2. Noun, singular or mass Refractor telescopes work just like microscopes and magnifying glasses, with a biconvex lens producing a focal point inside the body of the telescope, but the light continuing on to reach the eyepiece.