aberrations
ab*er*ra*tion
noun
{bc}the fact or an instance of deviating or being {d_link|aberrant|aberrant:1} especially from a moral {d_link|standard|standard:1} or normal state
chromatic aberration
noun
{bc}aberration caused by the differences in refraction of the colored rays of the spectrum
spherical aberration
noun
{bc}aberration that is caused by the spherical form of a lens or mirror and that gives different foci for central and marginal rays