Some that may be affected include Astigmatism,
coma, spherical, chromatic, and a few others;
depending upon the lens.
Likely diffraction limiting takes a visable toll only at
very small apertures; perhaps beyond f45. A mute
point when enlarging due to prolonged exposures.
Also, diffraction is a function of the absolute size
of the aperture. For example, two lenses at the
same aperture will exhibit diffraction in
proportion to their focal length. Dan