Electric contact lenses zoom in and out in a blink of an eye

Scientists have created contact lenses that can zoom in and out with a simple blink of the eye.

Scientist have developed contact lenses that can zoom in and out. Picture: Martin Lange

Scientists have created contact lenses that can zoom in and out with a simple blink of the eye.

The lenses can automatically switch between focusing on objects near or far away by tracking the wearer’s eye movements.

Researchers at the University of California created the robotic lens by mimicking the natural electric signals that occur in the human eyeball.

The lenses are made from stretchy polymer films encasing salt water that can change their structure when an electrical current is applied to them.

The researchers noted that there is an electric field in the ­tissues that surround the human eye and measurable difference in electrical voltage between the front and the back of the eye.

This is called an electro-­oculographic signal.

The scientists ­realised that when a person moves their eyes to look around or blink, that electrical signal can be measured and tracked by the lenses and ­respond accordingly. The team measured the electrical signals made when eyes make certain movements such as up, down, left, right, blink and double blink, and created a ­robotic lens that responds to those impulses.

They did this by placing five electrodes on the skin around the human eye that connect to the lens and activate when an electrical ­impulse is detected.

Researchers believe this could help people who are both long- and shortsighted. For example, looking down could cause the lens to focus on a page in a book, while looking up and ahead could lead the lens to ­adjust to focusing on a larger ­object further away.

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