Scientists have developed a new type of contact lenses that correct deuteranomaly, a form of red-green color blindness. They managed to create it by including in regular lenses some ultra-thin optical devices, known as metasurfaces.
“Problems with distinguishing red from green interrupt simple daily routines such as deciding whether a banana is ripe,” said in a statement Sharon Karepov from Tel Aviv University in Israel, one of the researchers in the research team. “Our contact lenses use metasurfaces based on nano-metric size gold ellipses to create a customized, compact, and durable way to address these deficiencies.”
The scientists believed their lenses could correct lost color contrast and enhance color perception up to about ten times. Moreover, they also suggest their approach could be used to help other eye disorders as well.
The important thing about the new lenses is that they are comfortable and practical to wear. Researchers have discovered ways of correcting deuteranomaly for over 100 years, but have done so using impractical methods.
“Glasses based on this correction concept are commercially available; however, they are significantly bulkier than contact lenses,” said Karepov. “Because the proposed optical element is ultrathin and can be embedded into any rigid contact lens, both deuteranomaly and other vision disorders such as refractive errors can be treated within a single contact lens.”
Metasurfaces at Work
That’s where metasurfaces come in. These are synthetically manufactured thin films created with optical attributes that can achieve certain effects on the light that’s coming through them. The team of researchers had one challenge with metasurfaces, though: getting them into the curved lens of contact lenses.
”We developed a technique to transfer metasurfaces from their initial flat substrate to other surfaces such as contact lenses,” said Karepov. “This new fabrication process opens the door for embedding metasurfaces into other non-flat substrates as well.”
The lenses are still to be clinically tested before they can be sold, but for color blind people, they provide a great hope of enhanced vision.
The research was published in the journal Optics Letters.