Light consists of individual particles that propagate in waves. The wavelength determines the color and energy of the light.

The human eye can only perceive a small section of this spectrum, approximately the range between 400 and 700 nanometers.

Because of that, we humans are unable to see the infrared range, with its longer wavelengths of 750 nanometers to one millimeter.

So in order to see infrared light, we have needed comparatively bulky night-vision goggles or night-vision devices with their own energy source — until now.

Researchers at the University of Science and Technology in Hefei, eastern China, have now developed a contact lens that converts infrared light into visible light, enabling humans to see in the dark.

Yuqian Ma and his team have combined conventional soft contact lenses with 45 nanometer particles consisting of gold, sodium gadolinium fluoride, ytterbium and erbium........

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