L
lens power
spherical lens: back- vertex power, expressed in dioptres (D) "cylindrical lens": back- vertex power in the principal meridian not equal to zero, excylindrical trial case lenses have one principal meridian with zero power.


spherical lens: back- vertex power, expressed in dioptres (D) "cylindrical lens": back- vertex power in the principal meridian not equal to zero, excylindrical trial case lenses have one principal meridian with zero power.