astigmatic power lens #01135
astigmatic power lens #01135
More specific terms
- NT1 ↓ BT: OIML
- NT1 ↓ DF: lens bringing a paraxial pencil of parallel rays to two separate line foci mutually at right angles and hence, unlike a spherical lens, having two principal powers
- NT1 ↓ NA: One of these powers may be zero, with the corresponding focal line at infinity. Lenses referred to as toric lenses, sphero-cylindrical lenses and cylinder lenses are all astigmatic.
- NT1 ↓ NC: ID: 01135
- NT1 ↓ NC: reference: R093:1999 3.10
