GRIN optical technology could mean better implantable lenses

Scientists have created lenses that refract light in the same fashion as the lens in the human eye (Photo: Shutterstock)


Although many people may think that the lenses in our eyes are just like those found in cameras, there is in fact one key difference between the two – while man-made lenses have just a single index of refraction, meaning that they only bend light in one direction, our natural lenses refract light by varying degrees. This is why artificial implanted lenses, such as those used to treat cataracts, can create visual distortions. A new technology, however, now allows for the fabrication of lenses that work just like the ones in our eyes.
The research was conducted by a team from Case Western University, the Rose-Hulman Institute of Technology, the U.S. Naval Research Laboratory, and Case Western spin-off company PolymerPlus.
The technology is known as GRIN (gradient refractive index optics), and involves creating a single lens from hundreds of thousands of layered and laminated nanoscale polymer films. Each of those films has slightly different optical properties, which results in light being incrementally bent by multiple degrees as it passes through the lens.

One of the finished GRIN lenses

“As light passes from the front of the human eye lens to the back, light rays are refracted by varying degrees,” said Michael Ponting, president of PolymerPlus. “It’s a very efficient means of controlling the pathway of light without relying on complicated optics, and one that we attempted to mimic.”
The obvious use for GRIN lenses would be as replacement lenses for human eyes. Due to the fact that they could reduce the number of components needed in optical systems, however, they may also find their way into consumer and military products.
A paper on the research was recently published in the journal Optics Express.
Source: The Optical Society, Gizmag