Imaging propertiesGlass lenses that are used in a light microscope fundamentallyshow imaging errors. These imaging errorscan be reduced to a practically insignificant level byoptical design measures.In general, imaging errors (aberrations) are understoodto mean deviations from the ideal diffractionlimitedimaging.Aberrations may affect microscopic images in differentways, e.g. through reduced contrast, poor resolutionor geometric distortions. Two types of aberrationswell known in microscopic systems are sphericaland color aberrations