Cataract surgery, a transformative procedure to restore vision, has seen remarkable advancements in intraocular lens (IOL) technologies. This special issue presents a collection of research that explores the performance, design, and evaluation of IOLs. From established designs and the impact of key optical parameters to innovative approaches and preoperative simulations, these contributions offer a comprehensive view of current trends and future directions in IOL development. The special issue also honors the legacy of Prof. Jim Schwiegerling whose contributions to visual optics in general, and IOLs in particular, have had a tremendous impact in the field, both in the academic, clinical and industrial communities.

Cataract surgery requires selecting an intraocular lens (IOL), whose design affects visual outcomes. Traditional IOL evaluation relies on optical models and bench testing, but these methods fall short in simulating perceptual factors crucial to patient experience. Visual simulators, based on different principles including adaptive optics, temporal multiplexing or physical projection of the IOLs, now allow patients and clinicians to preview and compare different IOL designs preoperatively. By simulating real-world interactions of the eye's optics and the visual system with IOLs, these simulators enhance the patient decision-making process, enable personalized cataract surgery, and can aid in regulatory assessments of IOLs by incorporating preoperative patient-reported visual outcomes. Visual simulators incorporate deformable mirrors, spatial light modulators and optotunable lenses as dynamic elements to simulate monofocal, multifocal and extended depth-of-focus IOLs, including newer designs aimed at improving contrast sensitivity, expanding depth of focus, and minimizing visual disturbances. With ongoing advancements, these simulators hold potential for transforming IOL design, regulatory processes, and patient care by providing realistic and patient-centered visual assessments, ultimately leading to more successful, individualized surgical outcomes.

A novel double-pass instrument and its data analysis method for the measurement of central and peripheral refraction is presented and validated in a group of healthy subjects. The instrument acquires in-vivo, non-cycloplegic, double-pass, through-focus images of the eye’s central and peripheral point-spread function (PSF) using an infrared laser source, a tunable lens and a CMOS camera. The through-focus images were analyzed to determine defocus and astigmatism at 0° and 30° visual field. These values were compared to those obtained with a lab-based Hartmann-Shack wavefront sensor. The two instruments provided data showing good correlation at both eccentricities, particularly in the estimation of defocus.

This study compares the effects on peripheral vision and image quality of four myopia control interventions: a) Perifocal spectacles/ArtOptica, b) Stellest spectacles/Essilor), c) MiyoSmart spectacles/Hoya and d) MiSight contact lenses/CooperVision. Five subjects participated with habitual or no correction as reference. Three techniques were used: 1) Hartmann-Shack sensors for wavefront errors, 2) double-pass imaging system for point-spread-functions (PSF), and 3) peripheral acuity evaluation. The results show that multiple evaluation methods are needed to fully quantify the optical effects of these myopia control interventions. Perifocal was found to make the relative peripheral refraction (RPR) more myopic in all subjects and to interact with the natural optical errors of the eye, hence showing larger variations in the effect on peripheral vision. MiSight had a smaller effect on RPR, but large effect on peripheral vision. Stellest and MiyoSmart also showed small effects on RPR but had broader double-pass PSFs for all participants, indicating reduced retinal contrast. Reduction in peripheral retinal contrast might thereby play a role in slowing myopia progression even when the peripheral refraction does not turn more myopic.

This feature issue collects articles presented at the tenth Visual and Physiological Optics meeting (VPO2022), held August 29–31, 2022, in Cambridge, UK. This joint feature issue between Biomedical Optics Express and Journal of the Optical Society of America A includes articles that cover the broad range of topics addressed at the meeting and examples of the current state of research in the field.

The accommodative response of the human eye is predominantly driven by foveal vision, but reacts also to off-foveal stimuli. Here, we report on monocular accommodation measurements using parafoveal and perifoveal annular stimuli centered around the fovea and extending up to 8 & DEG; radial eccentricity for young emmetropic and myopic subjects. The stimuli were presented through a sequence of random defocus step changes induced by a pupil-conjugated tunable lens. A Hartmann-Shack wavefront sensor with an infrared beacon was used to measure real-time changes in ocular aberrations up to and including the fourth radial order across a 3 mm pupil at 20 Hz. Our findings show a significant reduction in accommodative response with increased radial eccentricity.

This feature issue collects articles presented at the tenth Visual and Physiological Optics meeting (VPO2022), held August 29-31, 2022, in Cambridge, UK. This joint feature issue between Biomedical Optics Express and Journal of the Optical Society of America A includes articles that cover the broad range of topics addressed at the meeting and examples of the current state of research in the field.

In their pioneering work demonstrating measurement and full correction of the eye's optical aberrations, Liang, Williams and Miller, [JOSA A 14, 2884 (1997)] showed improvement in visual performance using adaptive optics (AO). Since then, AO visual simulators have been developed to explore the spatial limits to human vision and as platforms to test non-invasively optical corrections for presbyopia, myopia, or corneal irregularities. These applications have allowed new psychophysics bypassing the optics of the eye, ranging from studying the impact of the interactions of monochromatic and chromatic aberrations on vision to neural adaptation. Other applications address new paradigms of lens designs and corrections of ocular errors. The current paper describes a series of AO visual simulators developed in laboratories around the world, key applications, and current trends and challenges. As the field moves into its second quarter century, new available technologies and a solid reception by the clinical community promise a vigorous and expanding use of AO simulation in years to come.