To determine the through-focus optical bench test performance of monofocal, bifocal, and extended depth-of-focus intraocular lenses (IOLs), and to measure their defocus curves. Methods

A model eye was placed on an optical bench to test three different IOLs (TECNIS ZXR00, ZMB00, and ZCB00; Abbott Medical Optics, Santa Ana, CA, USA). The focus was changed by inserting trial lenses from +1.00 diopters to −4.00 diopters, in increments of +0.25 diopters. The 1951 United States Air Force Resolution chart was used to determine the quality of the images. The degree of similarity with reference images was given by the cross-correlation coefficient, and defocus curves were drawn and compared. Results

Bifocal IOLs showed lower image quality with the addition of minus diopter trial lenses, but showed good image quality at near distance. Bifocal IOLs also showed a ‘double peak’ in their defocus curve. Monofocal IOLs showed a lower image quality and cross-correlation coefficient with addition of lower-diopter trial lenses. The extended depth of focus IOLs showed a single peak in their defocus curve, but had a wider range of diopters and better image quality than monofocal IOLs. Conclusions

Bifocal IOLs showed a double peak defocus curve, and extended depth of focus IOLs showed a wider diopter range and better image quality than monofocal IOLs.