A
- Abbe number
- absorptance
- absorptive lens
- Active ophthalmic instrument
- addition power
- additive power trial case lens set
- Adjusting rail
- afocal lens
- aid microscope
- aid telescope
- alignment reference marking
- angular magnification
- antireflection coating
- apex
- apical angle
- arm
- as-worn power
- aspheric lens
- aspherical surface
- astigmatic difference
- astigmatic effect
- astigmatic lens power
- astigmatic power lens
- astronomical telescope
- atoric lens
- atoroidal surface
- auxiliary beam
- auxiliary lenses
atoric lens
Lens with astigmatic power in which at least one principal meridian is not spherical. At Carl Zeiss, the surface design of the atorus is adapted to every dioptric power, with the result that the best correction possible is achieved for both principal meridians. In Carl Zeiss progressive lenses, both atoroidal and aspheric surface design is used in order to obtain maximum visual quality.