Engineers have created a contact lens which can zoom in or out if the wearer blinks twice.
Researchers from the University of California San Diego created the biomimetic contact lens out of a special elastic polymer which can be pulled or relaxed to change the focal length.
The focal length is modified by making the lens material thicker or thinner in the same mechanism as muscles adapt the lens shape in human eyes, according to the paper published in Advanced Functional Materials.
Crucially, the decision to modify the lens shape is controlled by electric signals generated through eye movements in the researcher’s prototype, including even just blinking twice.
However, it might take a while before these lenses become viable products.
The prototype is currently sat in a large housing and requires an external power source, and if the lens on the eye itself is not too uncomfortable for wearers then the handful of wires used to power it are likely to prove a nuisance.
But this problem of miniaturisation is something that the past 50 years of technological advancement suggests will be overcome.
The more uncomfortable aspect are the electrodes which the wearers need to have around their eyes to detect the electrical signals from the muscle movements.
The researchers hope that the system could be used in visual prostheses and adjustable glasses in the nearer future, as well as in remotely operated robotics.