<h4>PURPOSE</h4><p>To measure the optical properties of multifocal intraocular lenses (IOLs) for different pupil sizes.</p> <h4>METHODS</h4><p>An artificial eye was fabricated that had both the average spherical aberration and chromatic aberration levels found in the human eye. This model eye contained a saline-filled wet cell into which various IOLs can be mounted. Pupil sizes of 3 and 6 mm were explored with the system. Using the model eye, the following IOLs were examined: Alcon ReSTOR apodized diffractive, AMO ReZoom zonal refractive, and Tecnis ZM900 full-aperture diffractive. The modulation transfer function (MTF) for the lenses was calculated. The model eye was also used as a portable device to photograph nighttime driving scenes.</p> <h4>RESULTS</h4><p>For 3-mm pupils, the apodized and full-aperture diffractive IOLs balance contrast between near and distance vision, whereas the zonal refractive IOL performs poorly for near vision. For 6-mm pupils, the apodized diffractive shifts performance from near vision to distance vision, whereas the zonal refractive and full-aperture diffractive IOLs continue to balance performance between distance and near. Subjectively, the night driving photographs showed much more stray light artifacts for the zonal refractive and the full-aperture and apodized diffractive IOLs.</p> <h4>CONCLUSIONS</h4><p>Under dark conditions, the shift of optical performance of the apodized diffractive lens towards distance vision reduces artifacts that appear under night driving conditions. These artifacts remain for the zonal refractive and full-aperture diffractive lenses. [<cite>J Refract Surg</cite>. 2008;24:218-222.]</p> <h4>ABOUT THE AUTHORS</h4> <p>From the College of Optical Sciences, Department of Ophthalmology, University of Arizona, Tucson, Ariz.</p> <p>The authors have no proprietary interest in the materials presented herein. Dr Schwiegerling receives grant and travel support from Alcon Laboratories Inc, Ft Worth, Tex.</p> <p>Correspondence: Jim Schwiegerling, PhD, Dept of Ophthalmology, 655 N Alvernon Way, Ste 108, Tucson, AZ 85711. Tel: 520.661.6504; E-mail: <a href="mailto:jschwieg@u.arizona.edu">jschwieg@u.arizona.edu</a></p> <p>Received: July 16, 2007</p> <p>Accepted: December 12, 2007</p>

Diffractive optical elements (DOEs), with their thin profile and unique dispersion properties, have been studied and utilized in a number of optical systems, often yielding smaller and lighter systems. Despite the interest in and study of DOEs, the application of DOEs has been limited to narrow spectral bands. This is due to DOEs depths, which are optimized for optical path differences of only a single wavelength, consequently leading to rapid decline in efficiency as the working wavelength shifts away from the design wavelength. Various broadband DOE design methodologies have recently been developed that improve spectral diffraction efficiency and expand the working bandwidth of diffractive elements. Two such extended bandwidth diffractive designs have been modeled and fabricated. The diffraction efficiency test result for one broadband DOE design is presented.

Diffractive optical elements, with their thin profile and unique dispersion properties, have been studied and utilized in a number of optical systems, often yielding smaller and lighter systems. Despite the interest in and study of diffractive elements, the application has been limited to narrow spectral bands. This is due to the etch depths, which are optimized for optical path differences of only a single wavelength, consequently leading to rapid decline in efficiency as the working wavelength shifts away from the design wavelength. Various broadband diffractive design methodologies have recently been developed that improve spectral diffraction efficiency and expand the working bandwidth of diffractive elements. We have developed diffraction efficiency models and utilized the models to design, fabricate, and test two such extended bandwidth diffractive designs. 4 5

Iris recognition utilizes distinct patterns found in the human iris to perform identification. Image acquisition is a critical first step towards successful operation of iris recognition systems. However, the quality of iris images required by standard iris recognition algorithms puts hard constraints on the imaging optical systems which have resulted in demonstrated systems to date requiring a relatively short subject stand-off distance. In this paper, we study long-range iris recognition at distances as large as 200 meters, and determine conditions the imaging system must satisfy for identification at longer stand-off distances.