PURPOSE: To obtain a small-sized, lightweight objective for video disk reproduction by using specific aspherical surfaces for both 1st and 2nd surfaces.

CONSTITUTION: The 1st and 2nd surfaces are both aspherical, and those aspherical surfaces are expressed by an equation I defining (h) as the height (h) from the optical axis, (x) as the distance of a corresponding aspherical surface peak from a tangential plane, (d) as the curvature at the aspherical surface peak, (k) as an ellipse constant, and AWD as aspherical surface constants and have various elements shown by II. In the equalities II, d1 is the thickness of a lens, d2 the thickness of a disk, N1 the refractive index of the lens 1 corresponding 780nm, and N2 the refractive index of the disk corresponding to 780nm. Consequently, a small-sized, lightweight lens with high performance is obtained as the objective for video disk reproduction.