Refractive extended depth-of-focus lens design based on periodic power profile for presbyopia correction.

Purpose: Limitations of existing diffractive multifocal designs for presbyopia correction include discrete foci and photic phenomena such as halos and glare. This study aimed to explore a methodology for developing refractive extended depth-of-focus (EDoF) lenses based on a periodic power profile.

Methods: The proposed design technique employed an optical power profile that periodically alternated between far, intermediate and near distances across the pupil radius.

Visual Axis and Stiles-Crawford Effect Peak Show a Positional Correlation in Normal Eyes: A Cohort Study.

Purpose: The purpose of this study was to locate the visual axis and evaluate its correlation with the Stiles-Crawford effect (SCE) peak.

Methods: Ten young, healthy individuals (20 eyes) were enrolled. An optical system was developed to locate the visual axis and measure SCE.

Binocular accommodative response with extended depth of focus under controlled convergences.

Vergence and accommodation can be mismatched under virtual reality viewing conditions, and this mismatch has been thought to be one of the main causes of visual discomfort. The goal of this study was to investigate how optical conditions of the eyes affect accommodative responses to different convergence. Specifically, we hypothesized that extending the depth of focus (DoF) could weaken the control of the screen on accommodation, so that accommodation could be induced by convergence.