While the pupil may be the opening in the eye that lets light through to the retina, the iris is the tissue that opens and closes to determine the size of the pupil. Although mechanical irises are already a standard feature in cameras, scientists from Finland and Poland have recently created an autonomous artificial iris that's much more similar to those found in the eye – it may even eventually be able to replace damaged or defective ones.
The contact lens-like device was created by researchers from Finland's Tampere University of Technology, along with Poland's University of Warsaw and Wrocław Medical University.
It's made from a polymer (a liquid crystal elastomer) that expands when exposed to light, then shrinks back when the light is lessened. This causes an opening in the middle to get smaller or larger, depending on the light levels – in this way, it works very much like a natural iris. Unlike automatic irises in cameras, it requires no power source or external light detection system.
With an "eye" towards one being able to use it as an optical implant, the scientists are now adapting it to work in an aqueous environment. They're also working at increasing its sensitivity, so that its opening and closing are triggered by smaller changes in the amount of incoming light.
The research is being led by Tampere's Prof. Arri Priimägi, and was recently described in a paper published in the journal Advanced Materials.
Source: Tampere University of Technology