Researchers have created novel new contact lenses that correct deuteranomaly, a form of red-green color blindness. They did so by incorporating ultra-thin optical devices known as metasurfaces into conventional lenses.
“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, a member of 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.”
Other eye disorders
The researchers believe their lenses can restore lost color contrast and improve color perception up to a factor of 10. Better yet, they also believe their approach could be adapted to help with other eye disorders.
The key to the new lenses is that they are actually comfortable and practical to wear. Scientists have known how to correct deuteranomaly for more than 100 years but have done so with impractical devices.
“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.”
That is where metasurfaces come in to play. These are artificially fabricated thin films designed with optical properties that can achieve specific effects on the light transmitted through them.
The researchers had one challenge with metasurfaces: getting them to fit on 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 still require clinical testing before they can be marketed, but for color blind people they offer great hope of improved vision.
The study was published in the journal Optics Letters.