A colour blind view on the left and a colour corrected on the right. Credit: Sharon Karepov/Tel Aviv University

Tel Aviv University researchers have found a way to incorporate ultra-thin metasurfaces into standard contact lenses, offering a convenient and comfortable way to correct various forms of colour blindness. 

Developed using simulations of colour vision deficiency, the metasurface-based contact lens can restore lost colour contrast and improve colour perception by up to a factor of 10, said researcher Sharon Karepov in Optical Letters. 

“Glasses based on this correction concept are commercially available, however, they are significantly bulkier than contact lenses. Because the proposed optical element is ultra-thin 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.” 

The thin, metasurface films are made of nanoscale gold ellipses and designed with specific optical properties.  

Metasurfaces have been extensively studied and can be designed to achieve specific effects on the light transmitted through them, explained Karepov. adding the main challenge for researchers was to find a way to fit the metasurfaces on the curved contact lens surface. “We developed a technique to transfer metasurfaces from their initial flat substrate to other surfaces. This new fabrication process opens the door for embedding metasurfaces into other non-flat substrates as well.”  

The metasurfaces’ light manipulation properties did not change after transfer to the curved surface, indicating that the process was successful, she said. 

Clinical testing is required for the contact lenses to be commercially available.