Purdue researchers develop new method for smart contact lenses

A research team at Purdue University has developed a method to pair commercially available soft contact lenses with bio-compatible sensors, effectively launching plans for a device that could help doctors better manage ocular disease and monitor other biological changes in their patients.

Chi Hwan Lee, an associate professor of biomedical engineering and mechanical engineering at Purdue, is the head researcher of the project, funded by the Purdue Research Foundation.

It’s not the first time developers have played with the idea. Novartis, an international health care company, partnered with Google in 2014 to build a "smart lens" prototype, which functions in many of the same ways as the technology proposed by Lee and his team.

But there are major obstacles for consumers in what bioengineering professionals currently know as the “smart lens,” Lee said. One, it's expensive, and, two, because the product is made from a thicker, plastic base, comfort and the length at which a user can wear the lens are limited.

Lee found in his experiments that hydrogel lenses like Acuvue can instead merge with thin sensor technology, a more comfortable, user-friendly alternative. Like the base soft contact lens, Lee's version of the smart lens can be worn up to 30 days and can be cleaned with normal contact solution.

His product is built using a thin, flexible strip of gold to conduct trace amounts of electricity embedded in the semi-transparent contact lens. A separate silicone membrane measures changes in the eye and other elements with which it is biocompatible.

"These current hydrogel-based contacts serve as the perfect platform for smart lens systems due to their high degree of comfortability, biocompatibility, breathability and long-term wearability," Lee said in a written explanation. "Before our discovery, it was challenging to fabricate high-performance electronics on commercially available soft contact lenses."

When used, this sensor can read temperature distribution on the surface of the eye, which could help optometrists and other medical professionals detect any abnormalities or symptoms from eye-related disease.

In the long term, Lee hopes to perfect the sensor to read other chemical changes in the body through the eye, such as a change in glucose levels.

At some point—though this will take many more trials and experimentation, Lee said—the lenses could be used for recreational or educational purposes by pairing them with augmented reality technology, which can superimpose virtual images on the eye so that they appear in a "real" space. Other potential uses include on-demand night vision or administering drugs via the lens for medical therapy.

His team recently secured a patent on the technology, with the help of Purdue's Office of Technology and Commercialization.

The next step, Lee said, is to ensure his request to test the technology on animals is approved, a process that could take six months to a year.

What is certain, he said, is that his team will partner with researchers at the Indiana University School of Medicine and test the technology on white rabbits, creatures that have eyes comparable to those of humans.

If the contact lenses move forward with approval by the U.S. Food and Drug Administration and commercialization, Lee hopes consumers can access the technology without spending an unreasonable amount of money. But that will largely depend on how insurance companies view the technology, he said.

"I hope these can be used in a very cost-effective way. That's been a big motivation of my research," Lee said in a phone call. "The smart contact lens is not new by any means, as companies like Google already have prototypes … But the soft lens we're using is ready for market."