% Lens 6 (Element 7):
R1        R1_7        Radius of curvature, surface 1
R2        R2_7        Radius of curvature, surface 2
Tc        Tc_7        Center thickness
d0        d0_7        Outer diameter
d1        d1_7        Diameter, surface 1
d2        d2_7        Diameter, surface 2
d1_clear  d1_clear_7  Clear aperture diameter, surface 1
d2_clear  d2_clear_7  Clear aperture diameter, surface 2
nix       0           Local optical axis, x-component
niy       0           Local optical axis, y-component
niz       1           Local optical axis, z-component