Photochromic materials are a class of substances that can usually change colors when they are exposed to the direct influence of certain wavelengths of light. They can most commonly be found in the lenses of sunglasses, or even in spectacles that change their color from transparent to black or brown when exposed to intense light from the sun, or bouncing off snow. The main drawback of existing photochromic materials (PM) is that they take a fairly long amount of time to change their colors, so Japanese researchers have looked at stamping that out by creating a type of PM that does that very fast.

The newly developed type of materials could lead to a host of new devices, and could easily be implemented in a number of technologies, including sunglasses, computers, dynamic holograms, and even some new types of drugs, researchers believe. Behind the innovation has been researcher Jiro Abe and his team, who have managed to significantly reduce the average time that existing photochromic materials need to change colors from several tens of seconds, or even hours, to less than a second, ScienceDaily reports.

Regular materials in this class, such as those currently available in sunglasses, tend to be a bit unstable and to have a long response time. That's why, until now, researchers around the world have had little success in converting them into efficient optical storage devices for advanced computers, or into “molecular switches,” for incorporating them in light-operated vaccine-delivery systems. Their use in other advanced applications has also been hindered by their ineffectiveness at doing the very task they were created to do in the first place.

The new material created in Japan shows a remarkable trait, in that it's able to display coloration just milliseconds after a beam of ultraviolet light is shone over it. At the same time, the coloration disappears within the same time-frame, after the source of light has been discontinued. The applications in the field of optics are remarkable, and could especially benefit those suffering from a deteriorating vision, who cannot stand to look at the bright sunlight. As soon as they exit their homes, the lenses on their spectacles could instantly become impenetrable for the UV radiation, and for a broad part of the visible light spectrum as well.