The structure of the lighting unit only consists of a spherical reflector and a primary lens which comprises an aspheric surface
and a spherical surface.
The optic zone diameter is 6.15 mm and incorporates a diffractive aspheric front surface and a posterior aspheric surface
with a negative spherical aberration of -0.11 microns for a 6.0 mm pupil diameter.
The experimental results showed that the two-axis UV polishing could polish the aspheric surface
roughness of a tungsten carbide mold to Rz 8 nm.
The retinal image size is reduced due to the aspheric surface
and flatter base curve; care must be taken to order both lenses from the same manufacturer to ensure that any MAR coatings or tints match.
In paper , an improved phase retrieval algorithm is proposed to overcome the measurement and calculation difficulty for aspheric surface
Lenses are limited by the inherent diffraction efficiency of the aspheric surface
, so they yield a lower overall transmission than comparable aspherized achromats.
The biggest challenge I faced making this scope was ensuring that the secondary's aspheric surface
was a smooth figure of revolution.
Roberts, "Characterization of the inherent error in a spherically-biased corneal topography system in mapping a radially aspheric surface
," Journal of refractive and corneal surgery, vol.
The human cornea is neither a true spherical, nor a true toric surface, but is a relatively complex aspheric surface
with the degree of asphericity varying in each of the principle meridians.
The IOLs have a biconvex design with an anterior aspheric surface
and a posterior diffractive surface.