A family of complex electron lenses, consisting of two coaxial double‐cylinder elements with unequal diameters, is investigated. It is concluded that the dominant contribution to the spherical aberration of such lenses arises in the accelerating component. Considerable reduction of the shperical aberration coefficient is possible in comparison with the unipotential and bipotential lenses customarily employed in cathode‐ray‐tube electron‐optical systems.