Our online medical glossary of medical terms and definitions includes definitions for terms related to treatment, and general medicine
ABERRATION, SPHERICAL
A lensdefect whereby image forming rays of one colour, passing throughthe outer zones of a lens come to focus at a various distance from the lens than do those of more central rays.
With a simplespherical (or plano-spherical) lensthe outer rays always meet the axis closer to the lens than do more central rays and the lens is uncorrected or undercorrected. When the reverse is true the lens has been overcorrected.