Researchers at Nottingham Trent University have created an artificial eye with a cosmetic pupil that can dilate and contract in response to light.
"The prototype aims to solve the longstanding problem of eye loss victims having two different sized pupils at night or in bright sunshine. Although artificial eyes today often appear lifelike, none on the open market feature a pupil which can change in size like a real eye," said the University.
The pupil is a dielectric elastomer actuator (DEA) made from a soft silicone disc with stretchable carbon electrodes on each side.
Applying a voltage across the electrodes causes electrostatic force which squashes the disc, making it thinner and wider.
In an over-sized prototype eye, this took 1.5kV at 660μA (1W).
The prototype is made from acrylic resin and powered by a battery. It includes a light sensor and controller to calculates how much power is needed to achieve the appropriate size pupil.
Dr Philip Breedon over-saw the 18 month research programme, which was carried out with Nottingham-based John Pacey-Lowrie Ocular Prosthetics.
“There is a lot more work to be done, but we are pleased with some of the initial results as they are very encouraging," said Breedon. “It will no doubt be a real challenge to miniaturise the prototype to the smaller size which is needed, but it is something that we believe can be achieved.”
“Many people who have a prosthetic eye are very conscious of how realistic it looks," said John Pacey-Lowrie, who has worked in ocular prosthetics for 35 years and thought-up the automatic pupil concept. His company already makes eyes that are moved by remnant eye muscles.
