Subtle, regular and measureable imperfections in a lens or optical system that is not corrected with simple sphero-cylindrical lenses. An astronomer and mathematician in the early 20th Century named Fritz Zernike developed a series of polynomial equations to describe low- and higher-order aberrations in lathe-cut lenses. These Zernike polynomials form the basis for analysis and description of aberration patterns in many current systems designed for wavefront analysis of the human eye, including the Alcon Custom Cornea; Bausch & Lomb Zyoptix and Visx WaveScan systems.
