New Spiral-Shaped Lens Designed to Improve Vision at Range of Distances and Lighting Conditions

French researchers have developed a spiral-shaped lens that is designed to maintain clear focus at different distances in varying light conditions. Published in the journal Optica,¹ the researchers say the lens works much like progressive lenses used for vision correction but without the distortions typically seen with those lenses. Its spiraling features are arranged in a way that creates many separate points of focus—much like having multiple lenses in one. This makes it possible to see clearly at various distances, the researchers said in an Optica Publishing Group news release.

“Unlike existing multifocal lenses, our lens performs well under a wide range of light conditions and maintains multifocality regardless of the size of the pupil,” said Bertrand Simon from the Photonics, Numerical and Nanosciences Laboratory (LP2N), a joint research unit between the Institut d'Optique Graduate School, the University of Bordeaux, and the CNRS in France. “For potential implant users or people with age-related farsightedness, it could provide consistently clear vision, potentially revolutionizing ophthalmology.”

Spiral diopter lens - Researchers have developed a new type of lens that uses a spiral-shaped surface to maintain a clear focus at different distances in varying light conditions.

Credit: Laurent Galinier

“In addition to ophthalmology applications, the simple design of this lens could greatly benefit compact imaging systems,” said Mr. Simon. “It would streamline the design and function of these systems while also offering a way to accomplish imaging at various depths without additional optical elements. These capabilities, coupled with the lens's multifocal properties, offer a powerful tool for depth perception in advanced imaging applications”

The researchers created the lens by using advanced digital machining to mold the unique spiral design with high precision. They then validated the lens by using it to image a digital ‘E,’ much like those used on an optometrist's light-up board. The authors observed that the image quality remained satisfactory regardless of the aperture size used. They also discovered that the optical vortices could be modified by adjusting the topological charge, which is essentially the number of windings around the optical axis. Volunteers using the lenses also reported noticeable improvements in visual acuity at a variety of distances and lighting conditions.

The researchers are now working to better understand the unique optical vortices produced by their lens. They also plan to perform systematic trials of the lens’ ability to correct vision in people to comprehensively establish its performance and advantages in real-world conditions. In addition, they are exploring the possibility of applying the concept to prescription eyeglasses, which could potentially offer users clear vision across multiple distances. 

To access the full study in Optica, click here. 

References

1.  L. Galinier, P. Renaud-Goud, J. Brusau, L. Kergadallan, J. Augereau, B. Simon, “Spiral diopter: Freeform lenses with enhanced multifocal behavior,” Optica. 11, 238-244 (2024). DOI: 10.1364/OPTICA.507066.