Application of the polychromatic defocus transfer function to multifocal lenses.

PURPOSE: To model the performance of multifocal lenses in polychromatic lighting.

METHODS

The defocus transfer function (DTF) is a mathematical technique for illustrating the optical transfer function for all levels of defocus at a given wavelength. A polychromatic version of the DTF is developed that accounts for changes in cutoff frequency, reduction in diffraction efficiency, ocular chromatic aberration, and photoreceptor spectral sensitivity. The differences between the monochromatic and polychromatic DTF are illustrated with a diffractive multifocal intraocular lens.

RESULTS

Polychromatic analysis shows an increase in depth of field of diffractive lenses relative to assessment at a single wavelength.

CONCLUSIONS

The polychromatic DTF is a useful tool for analyzing presbyopia treatments under "white-light" viewing conditions and provides feedback to lens designers on anticipated performance.