Simple multifocal lens based on liquid crystals

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Design and modelling of thermoformed displays for smart contact lenses

This paper explores the challenges regarding the thermoforming of a deformable guest-host liquid crystal display within a smart contact lens. Focus was given to the finite element modelling of its thermoforming, to find respective design rules. Such displays are thought to be used in vision correction applications (i.e. artificial iris)

A biocompatible active artificial iris

A contact lens mimicking an artificial iris is presented as solution for people suffering from iris deficiencies. As this is a biomedical device, biocompatibility is a key specification for material choice and design. The presented research focusses on oxygen permeability of the lens, as the eye depends on oxygen from the environment for functioning

Artificial iris performance for smart contact lens vision correction applications

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/m(2)), 2D (10 cd/m(2)) and 0.75D (1 cd/m(2)). 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

An artificial iris ASIC with high voltage liquid crystal driver and 10nA light range detector and 40nA blink detector for LCD flicker removal

In a functional eye, the iris controls the pupil diameter to regulate the exposure of the retina. While iris deficiencies such as aniridia or leiomyoma can be mitigated with fixed or adaptive artificial irises [1] and adaptive transparency glasses exist to alleviate this situation, they do not mimic the normal functionality of the natural iris. To address this, a fully encapsulated, self-contained artificial iris embedded in a smart contact lens is proposed. A control ASIC is developed in 0.18 μm 16 V BCD TSMC with typ. 1.9 μw current consumption from 3 V supply voltage at office light condition