Abstract: A lens element is disclosed which satisfies the following three conditions______________________________________ .vertline..DELTA.h/R.vertline. .gtoreq. 0.1 . . . Condition (1) .PHI. .ltoreq. 8 mm . . . Condition (2) Tg .ltoreq. 530.degree. Centigrade . . . Condition (3) ______________________________________where .DELTA.h is the change in height of the lens element surface as measured from the lens element vertex to its edge, R is radius of curvature of the lens element near the optical axis, .PHI. is the outer diameter of the lens element, and Tg is the glass transition point of the lens element. Further, if the optical material of the lens element includes lead, then its glass transition point Tg must be no more than 490 degrees to avoid the lead being precipitated onto the surface of the mold during the pressing, thereby forming a defect in the lens element.