Scientists have designed a surprising new contact lens that could revolutionize ophthalmology. It is based on a spiral pattern that allows the eye to focus at different distances and in different lighting conditions.
Beyond contact lenses, its inventors say the technology could be applied to a variety of miniaturized imaging systems, including consumer devices such as virtual reality headsets, to offer more versatility and flexibility than existing lenses.
The lens, called a spiral diopter, causes incoming light to spin in an optical vortex, taking into account the various deformations in the eye’s cornea that can occur as we age.
“Unlike existing multifocal lenses, our lenses perform well in a wide range of light conditions and maintain multifocality regardless of pupil size,” says Bertrand Simon of the Laboratory of Photonics, Numerics and Nanosciences (LP2N) in France.
“For potential implant users or people with age-related farsightedness, it could provide clear and constant vision, potentially revolutionizing ophthalmology.”
At this time, older people with conditions such as farsightedness and cataracts can use progressive lenses to focus at different distances, and different parts of the glass have different magnification powers.
Here, everything is brought together in a single lens, also much smaller, and without the distortions that can occur in the user’s peripheral vision, thanks to the application of a spiral based on the Fermat spiral.
While researchers are still far from being able to mass produce spiral diopter contact lenses, they have performed simulations and laser tests that show the lens works as intended. Experiments with volunteers have also given promising results.
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“To create an optical vortex you usually need several optical components,” says Laurent Galinier of the optics company SPIRAL SAS in France. “Our lens, however, incorporates the elements necessary to form an optical vortex directly on its surface.”
“Creating optical vortices is a thriving field of research, but our method simplifies the process, marking a significant advance in the field of optics.”
This is all very positive, but there is still a lot of work to do: the team says more research is needed to understand the exact nature of the optical vortices (or twisted light) produced by spiral diopter.
After that, the technology will need to be tested in glasses for people with less than perfect vision, in real-world scenarios. The researchers also mention a variety of other applications in cameras for everything from drones to self-driving cars.
“In addition to ophthalmic applications, the simple design of this lens could greatly benefit compact imaging systems,” says Simon.
“It would streamline the design and function of these systems while providing a way to achieve imaging at various depths without additional optical elements.”
The research has been published in OPTICAL.