ABERRATION n.
The convergence to different foci, by a lens or mirror, of rays of light emanating from one and the same point, or the deviation of such rays from a single focus; called spherical aberration, when due to the spherical form of the lens or mirror, such form giving different foci for central and marginal rays; and chromat…
CONVERGING a.
Tending to one point; approaching each other; convergent; as, converging lines. Whewell. Converging rays(Opt.), rays of light, which, proceeding from different points of an object, tend toward a single point. -- Converging series (Math.), a series in which if an indefinitely great number of terms be taken, their sum w…