A new prototype contact lens will allow color blind people to distinguish colors. Laboratory modeling has shown that they improve color perception up to ten times.
Typically, the human eye can distinguish about 1 million colors. A new type of contact lens can restore part of this range in people with color blindness, whose perception is limited in some parts of the spectrum.
A solution for some types of blindness is already available in the form of smart sunglasses with frequency filtering. Now, engineers Sharon Karepov and Tal Ellenbogen from Tel Aviv University in Israel have come up with a way to transfer color-correcting films to the surface of contact lenses.
The researchers explained that color blindness occurs due to several abnormalities when the visual system incorrectly determines the different wavelengths of light. At the back of the eyeball are receptors – three types of photosensitive cone cells that absorb waves and transmit a message about it to the brain.
The first type of pigment has a maximum sensitivity to short types of waves, the second to medium, and the third to long. People without visual impairment have in the cones all three pigments in the required amount. However, when part or all of the pigment is absent, problems arise with the perception of colors. Most often – with the perception of medium or long waves.
A few years ago, material scientist Don MacPherson came to the conclusion that a mixture of rare earth metals embedded in a transparent material can scatter waves in such a way that the right level of light filtration is achieved. Researchers from Israel have also used this method in their lenses. They also rely on the optical properties of meta-surfaces, which are designed to change the way light is reflected and transmitted in a material.
“Our contact lenses use meta-surfaces based on nanometer-sized gold ellipses to create an individual, compact, and durable way to eliminate color rendering,” the researchers noted. The lens has not yet been proven effective in clinical trials. Laboratory simulation using a test showed that they can help improve color perception up to ten times.