Artificial iris performance for smart contact lens vision correction applications

Andrés Vásquez Quintero,Herbert De Smet,Pablo Pérez-Merino

doi:10.1038/s41598-020-71376-1

Andrés Vásquez Quintero, Herbert De Smet + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-71376-1

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Abstract

This paper presents the simulated performance assessment of an artificial iris embedded on a scleral contact lens using real data from an aniridia patient. The artificial iris is based on guest–host liquid crystal cells (GH-LCD) in order to actively modify the transmittance of the lens and effective pupil size. Experimental validation of the GH-LCD spectrum and iris contrast (determined to be 1:2.1) enabled the development of optical models that include the effect of a small pupil on image quality and visual quality on an optical system with aniridia characteristics. Visual simulations at different light conditions (high/low photopic and mesopic) demonstrated the theoretical capacity of the customized artificial iris smart contact lens to expand the depth-of-focus and decrease the optical aberrations (in particular, the spherical aberration). The visual modelling suggests a maximum depth-of-focus value for a 2-mm pupil diameter for both eyes as follows: 3D (1,000 cd/m2), 2D (10 cd/m2) and 0.75D (1 cd/m2). This work demonstrates the beneficial optical effects of an active artificial iris, based on visual simulations in response to different light levels, and enables further experimental investigation on patients to validate the dynamic light attenuation and visual performance of smart contact lenses with GH-LCD.

Highlights

This paper presents the simulated performance assessment of an artificial iris embedded on a scleral contact lens using real data from an aniridia patient
Using a white light optical setup and CMOS camera, optical images of the stimulus were analyzed in order to assess their qualitative optical quality and visible light transmittance (VLT) values during the operation of the active GH-LCD cells
This study represents, to our knowledge, the first report of (1) on-bench measurements of light transmission and image quality of an active artificial iris and (2) simulations based on real data from an aniridia patient to evaluate the optical performance and depth-of-focus for different light level conditions

Summary

Introduction

This paper presents the simulated performance assessment of an artificial iris embedded on a scleral contact lens using real data from an aniridia patient. This work demonstrates the beneficial optical effects of an active artificial iris, based on visual simulations in response to different light levels, and enables further experimental investigation on patients to validate the dynamic light attenuation and visual performance of smart contact lenses with GH-LCD. Controlled transmittance changes of every ring make the GH-LCD technology an interesting approach to create an active artificial iris embedded within a contact lens; opening extraordinary possibilities in patients with aniridia by attenuating the light intensity through the ocular media and offering new options for presbyopia correction by expanding depth-of-focus with an automatic control of the pupil size. The natural human pupil changes by approximately 15-fold under varying levels of luminance, with dilation in low light conditions and constriction with bright light The loss of this natural adaptive response may lead to photophobia, glare, halos, an increase of aberrations (monochromatic and chromatic) and, a decreased visual a cuity[26]. These are passive solutions with potential limitations as de-centration, reduction in the visual field, decrease in the contrast sensitivity and artifacts in the retinal image quality (mainly due to the increased diffraction effect, distortions in the perception of relative movement or vignetting)

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