Imec and UGent develop electronic contact lenses

Ghent University and the imec research institute are working on an electronic contact lens that mimics almost the full functionality of a human iris. In time, patients with a damaged or missing iris should be able to use the lens.

The developed electronic lens can dynamically change the pupil size with the control of thin electronics and with low consumption. Charging can be done wirelessly, according to the makers, via nfc. The University of Ghent and imec have a prototype ready and have shown that it functions under different lighting conditions. They also performed simulations based on 3-D data of a patient with aniridia, an eye abnormality in which the iris is partially or completely missing.

According to imec, there are already techniques for artificially controlling the amount of light entering the eye, such as contact lenses, iris implants or glasses with variable transparency. But these techniques are limited and do not provide sharp vision, for example. The human iris regulates the incidence of light by narrowing or widening the pupil and the researchers tried to simulate this as closely as possible with their prototype and also improve the depth of field.

They built the artificial iris from four rings of liquid crystals, with a total width of 6mm and a thickness of 100 to 150μm. This so-called HG-LCD is able to vary the transmission of light, depending on the application of an electric field between parallel electrodes. The hg-lcd is combined with an asic that includes a photodiode for detecting light and an ‘eye blink detector’. The whole consumes only 148nW and thanks to the integration of nfc, the iris can be charged wirelessly. The scientists are experimenting with the use of a photovoltaic cell for food.

The spin-off Azalea Vision was founded to market the electronic contact lens for people with eye conditions that lead to reduced light sensitivity and depth of field. The artificial iris was developed by the Center for Microsystems Technology of imec and Ghent University, but the Holst Center of TNO and the Spanish Instituto de Investigación Sanitaria Fundación Jiménez Díaz also contributed. The research is published in Scientific Reports of Nature, under the title Artificial iris performance for smart contact lens vision correction applications.