Ophthalmic devices, such as contact lenses (CLs), or intraocular lenses (IOLs) require a clear lens with minimal glistening for optimal retinal image quality. Glistenings, which are scattering centers in ophthalmic lenses, induce light scatter and can degrade visual performance. To better understand the visual impact of lens glistening, an optical model was developed to quantitatively investigate the optical performance of an ophthalmic device with different magnitudes of glistening. Scattering centers, with different sizes and density, were incorporated into a phantom ophthalmic lens to simulate overall lens-eye system optical modulation transfer function (MTF). Blur images, due to ophthalmic device glistering, were simulated. To understand the interactions among MTF value reduction, simulated retinal image degradation and patient’s subjective response, Just Noticeable Difference (JND), which is the amount of change in vision that is just noticeable when compared with the prior state, is employed to quantify patient’s subjective response to blur images. As an example, with a 0.25% volume density of 10-μm scattering centner, a 3JND patient’s visual perception degradation was computed for a 4-mm pupil size comparing with a scattering-free case.
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