Extended aspheric surface
formulations provide improved manufacturability
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.
Numerical Control Interpolation Algorithm of Aspheric Surface
Based on the Genetic Algorithms and Neural Network
One of the technical highlights is the plastic "combiner" screen, which has an aspheric surface
31) In an attempt to minimise these symptoms, many MIOL designs incorporate an aspheric surface
to maximise contrast sensitivity and visual function.
Clinical studies have not been conducted with the Akreos Advanced Optics Aspheric lens to assess the effect of the added aspheric surface
to the parent lens model Akreos on spherical aberration, visual acuity and contrast sensitivity.
Therefore an aspheric surface
is spherical at the very centre but becomes astigmatic away from the optical centre.
The hydrophobic acrylic material helps lower chromatic dispersion for improved vision and the lens uses a patented, wavefront-designed aspheric surface
to compensate for spherical aberration of the cornea.
Interferometric asphere metrology has traditionally required the use of a null lens or computer-generated hologram that must be specially designed for each different aspheric surface
Unilens contact lenses have a unique aspheric surface
that corrects vision needs without the dependence on lens orientation, image selection or image suppression, which have been issues with bifocal contact lenses.
Current optical design of optical instruments is based on conic or aspheric surfaces
of revolution (both on-axis and off-axis).
The Crystalens AO has prolate aspheric surfaces
and is designed to be free of spherical aberration.