herical
aberration (SA3) and third order coma (CMA3) change when manufacturing
tolerances are applied to the first element of the design. Before the
impact of these manufacturing tolerances are evaluated, the lens will
be refocused using an automatic adjustment of the thickness of surface
#8 so that the paraxial marginal ray height, PY, at the image surface
is restored to its original value prior to the application of the
manufacturing tolerances. It's really very easy to do. Simplicity
itself. Read the TOL