Calculation of Phakic and Pseudophakic Additional Lenses

Calculation of add-on intraocular lens (IOL) power, both for phakic and pseudophakic eyes, can be done based on refraction, spectacle vertex distance, corneal curvatures, and IOL plane position. In this chapter, a Gaussian optical matrix formalism is described allowing for the calculation of IOL power and lateral magnification. This method is based on a system matrix, which describes and characterizes the paraxial optical properties of the relevant optical part of the eye. This system matrix is composed of a product of refraction and translation matrices. The power of non-toric and toric lenses can be calculated in this way. The power and magnification of non-toric add-on lenses can also be easily estimated with a polynomial linear model.