Abstract
Purpose::
To measure the optical performance of multifocal intraocular lenses (IOLs) for different pupil sizes.
Methods::
An artificial eye has been fabricated that has both the average spherical aberration and chromatic aberration levels found in the human eye. This model eye contains a saline-filled wet cell into which various IOLs can be mounted. Pupil sizes of 3, 4.5 and 6 mm can be explored with the system. We examined the Alcon ReSTOR apodized diffractive IOL and AMO ReZoom zonal refractive IOL with the model eye. First, the Line Spread Function (LSF) was measured with each lens. The Modulation Transfer Function (MTF) for the lenses is then calculated from the LSF. In addition, the model eye was attached to a commercial digital camera and a nighttime driving scene was photographed.
Results::
For 3 mm pupils, the apodized diffractive IOL balances contrast between the near and distant vision, while the zonal refractive IOL performs poorly for near vision. For 6 mm pupils, the apodized diffractive shifts performance from near vision to distance vision, while the zonal refractive balances performance between distance and near. Subjectively, the night driving photographs showed much more stray light artifacts for the zonal refractive with a large pupil.
Conclusions::
Under dark conditions, the shift of optical performance of the apodized diffractive lens towards distance vision reduces artifacts that can appear under night driving conditions. These artifacts remain for the zonal refractive lenses.
Keywords: intraocular lens • optical properties • presbyopia