2-D Peripheral image quality metrics with different types of multifocal contact lenses

Abstract

To evaluate the impact of multifocal contact lens wear on the image quality metrics across the visual field in the context of eye growth and myopia control. Two-dimensional cross-correlation coefficients were estimated by comparing a reference image against the computed retinal images for every location. Retinal images were simulated based on the measured optical aberrations of the naked eye and a set of multifocal contact lenses (centre-near and centre-distance designs), and images were spatially filtered to match the resolution limit at each eccentricity. Value maps showing the reduction in the quality of the image through each optical condition were obtained by subtracting the optical image quality from the theoretical physiological limits. Results indicate that multifocal contact lenses degrade the image quality independently from their optical design, though this result depends on the type of analysis conducted. Analysis of the image quality across the visual field should not be oversimplified to a single number but split into regional and groups because it provides more insightful information and can avoid misinterpretation of the results. The decay of the image quality caused by the multifocal contacts alone, cannot explain the translation of peripheral defocus towards protection on myopia progression, and a different explanation needs to be found.

Myopia Control Effect Is Influenced by Baseline Relative Peripheral Refraction in Children Wearing Defocus Incorporated Multiple Segments (DIMS) Spectacle Lenses

“…There is a decreasing range of defocus for eye compensation from mice, avian, to primate; thus, we assume that humans may have a narrow range of defocus power where eye growth can be manipulated. Garcia et al [36] reported in a study that superimposing myopic defocus for compensating hyperopic RPR in myopes, in some cases, could degrade the peripheral image quality. DIMS lens wearers with baseline myopic RPR received too much myopic defocus at the mid-periphery retina, which can result in an overall peripheral image blur beyond the threshold of signal detection, and myopia control would therefore be less effective [37,38].…”