infrared contact lenses human night vision

Revolutionary Lenses Allow Humans to See in the Dark Without Opening Eyes

A Breakthrough in Noninvasive Vision Enhancement

A team of neuroscientists and materials scientists has developed contact lenses that grant infrared sight in humans and mice by transmuting infrared into visible light. Unlike traditional night-vision googles, these lenses—reported in Cell—need no external power and allow perception of several infrared bands. Their transparency permits simultaneous viewing of infrared and visible light, with superior IR vision when the eyes are closed.

"Our findings pave the way for wearable, noninvasive technologies that could grant humans enhanced vision," remarks Tian Xue, lead researchers and neuroscientist at the University of Science and Technology of China. "The material offers immediate possibilities—flickering infrared light, for instance, may serve to relay data in contexts such as security, rescue operations, encryption or anti-counterfeiting."

How the Infrared Contact Lenses Work

Nano-particles Convert Infrared to Visible Light

The contact lens employs nano-particles capable of absorbing infrared radiation and converting it into light within the visible spectrum (approximately 400 to 700 nanometers), perceivable by mammalian eyes. These particles are designed to detect near-infrared wavelengths, ranging from 800 to 1600 nanometers—just beyond the natural limits of human vision.

Earlier Research and Motivation

The researchers had earlier demonstrated that injecting these nano-particles into the retina could grant mice infrared vision, though their aim was to develop a less intrusive alternative.

Design and Testing of the Contact Lenses

Safe Integration with Soft Lens Polymers

The researchers fashioned the contact lenses by integrating the nano-particles with pliable, non-toxic polymers commonly found in conventional soft lenses. Upon confirming their safety, the lenses were tested on both humans and mice.

Mice Behavioral Evidence of Infrared Vision

The researchers observed that mice fitted with contact lenses exhibited behaviors indicative of infrared vision. When offered a choice between a dark enclosure and one lit with infrared light, lens-wearing mice opted for the dark, unlike their untreated counterparts.

Physiological and Brain Activation Indicators

The mice exhibited physical indicators of infrared vision, with their pupils narrowing in response to infrared light. Imaging also showed activation in the brain's visual processing centers when exposed to such wavelengths.

Human Trials and Performance

Recognition of Infrared Signals

Human participants wearing the infrared contact lenses were able to correctly identify flickering Morse code-style signals and determine the source direction of the infrared light.

"It's perfectly straightforward-without the contact lenses, the subjects sees nothing. With them on, they can plainly observe the flickering of the infrared light," remarked Xue.

Closed-Eye Detection Advantage

"We discovered that subjects were better at detecting the flickering when their eyes were closed, as near-infrared light passes through the eyelids more efficiently than visible light, reducing interference."

Multiband and Colour-Coded Infrared Vision

Assigning Colours to Infrared Wavelengths

A further modification to the lenses enables wearers to distinguish among various bands of infrared light, with nanoparticles designed to assign distinct colours to each wavelength—such as blue for 980 nm, green for 808 nm and red for 1,532 nm.

Aid for Colour-Blind Users

Beyond enhancing perception of infrared details, the colour-coded nanoparticles may also be adapted to assist those with colour blindness in detecting wavelengths they typically cannot see.

"Through converting red wavelengths into green ones, this innovation could help blind users perceive previously invisible elements," says Xue.

Improving Visual Clarity and Signal Detection

Wearable Glasses for Sharper Infrared Imaging

Due to the contact lenses' limited capacity for fine detail—owing to their closeness to the retina causing scattered light—the researchers devised a wearable glass system using the same nanoparticles, offering sharper infrared perception.

Future Developments in Sensitivity

At present, the contact lenses can solely detect infrared light emitted by LED sources, though scientists are striving to enhance the nanoparticles' sensitivity to pick up weaker infrared signals.

"In time, through collaboration with materials scientists and optics specialists, we aim to develop a contact lens boasting finer resolution and improved sensitivity," said Xue.

Source

Learn more on FSNews365—your source for deep dives into frontier science, AI, tech, space and next-gen innovation reshaping the world.

Explore more on Earth Day Harsh Reality—a platform focused on the intersection of technology, sustainability and the stark truths of environmental change.

Read the full story via Human Health Issues—a blog dedicated to exploring revolutionary advancements in health, medicine and the human body.