High-tech contact lenses correct color blindness

These images illustrate the effect a metasurface-based contact lens would have on a person with deuteranomaly. The left image shows the original scenario while the middle image is how the scene would look to a person with deuteranomaly. The image on the right represents the scene viewed with deuteranomaly and corrected with the new contact lenses. Credit: Sharon Karepov, Tel Aviv University

Researchers have incorporated ultra-thin optical devices known as metasurfaces into off-the-shelf contact lenses to correct deuteranomaly, a form of red-green color blindness. The new customizable contact lens could offer a convenient and comfortable way to help people who experience various forms of color blindness.

“Problems with distinguishing red from green interrupt simple daily routines such as deciding whether a banana is ripe,” said 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.”

In The Optical Society (OSA) journal Optics Letters, Karepov and colleagues report that, based on simulations of color vision deficiency, their new metasurface-based contact lens can restore lost color contrast and improve color perception up to a factor of 10.

The approach used to introduce new and tailor-designed functionalities to contact lenses could be expanded to help other forms of color vision deficiency and even other eye disorders, according to the researchers.

Customized correction

Deuteranomaly, which occurs mostly in men, is a condition in which the photoreceptor responsible for detecting green light responds to light associated with redder colors. Scientists have known for more than 100 years that this vision problem can be improved by reducing detection of the excessively perceived color but achieving this correction in a comfortable and compact device is challenging.

“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.”

To solve this problem, the researchers turned to metasurfaces — artificially fabricated thin films designed with specific optical properties. Metasurfaces made of nanoscale gold ellipses have been extensively studied in the past few decades and can be designed to achieve specific effects on the light transmitted through them. However, the researchers needed a way to get metasurfaces, which are conventionally made on flat surfaces, onto the curved surfaces 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.”

From a flat to curved surface

The researchers tested the optical response of the metasurface after every step of the new fabrication procedure and acquired microscopy images to closely examine the structure of the metasurface. Their measurements showed that the metasurface's light manipulation properties did not change after transfer to the curved surface, indicating that the process was successful.

The researchers then used a standard simulation of color perception to quantify the deuteranomaly color perception before and after introducing the optical element. They found an improvement of up to a factor of 10 and showed that visual contrast lost due to deuteranomaly was essentially fully restored.

Although clinical testing would be needed before the contact lenses could be marketed, the researchers say that manufacturers could embed the metasurface during the molding stage of contact lens fabrication or thermally fuse them to a rigid contact lens. They plan to keep studying and improving the metasurface transfer process and test it for other applications.

###

Funding for the research was provided by the generosity of Eric and Wendy Schmidt by recommendation of the Schmidt Futures program

Paper: Sharon Karepov and Tal Ellenbogen, “Metasurface based contact lenses for color vision deficiency,” Opt. Lett., 45, 6, 1379-1382 (2020). DOI: https://doi.org/10.1364/OL.384970.

About Optics Letters

Optics Letters offers rapid dissemination of new results in all areas of optical science with short, original, peer-reviewed communications. Optics Letters accepts papers that are noteworthy to a substantial part of the optics community. Published by The Optical Society and led by Editor-in-Chief Miguel Alonso, Institut Fresnel, Ecole Central Marseille and Aix-Marseille Université, France, University of Rochester, USA, Optics Letters is available online at OSA Publishing.

About The Optical Society

Founded in 1916, The Optical Society (OSA) is the leading professional organization for scientists, engineers, students and business leaders who fuel discoveries, shape real-life applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership initiatives, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of optics and photonics experts. For more information, visit osa.org.

Media Contact: mediarelations@osa.org

Media Contact

James Merrick
jmerrick@osa.org
202-416-1994

 @opticalsociety

http://www.osa.org 

All latest news from the category: Medical Engineering

The development of medical equipment, products and technical procedures is characterized by high research and development costs in a variety of fields related to the study of human medicine.

innovations-report provides informative and stimulating reports and articles on topics ranging from imaging processes, cell and tissue techniques, optical techniques, implants, orthopedic aids, clinical and medical office equipment, dialysis systems and x-ray/radiation monitoring devices to endoscopy, ultrasound, surgical techniques, and dental materials.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors