wavefront The surface formed by each point in a propagating wave that are of equivalent phase, they are most often planar or spherical, and sometimes cylindrical. Related MicroscopyU Article Perfect Lens Characteristics The simplest imaging element in an optical microscope is a perfect lens, which is an ideally corrected glass element that is free of aberration and focuses light onto a single point. This tutorial explores how light waves propagate through and are focused by a perfect lens.