The technology has potential for applications in contact lenses and intraocular implants
Research findings published in Optica indicate a new spiral lens could provide similar benefits to progressive lenses, with less visual distortion than those solutions currently on the market. The investigators’ findings, as described by Optica Publishing Group in a news release, demonstrate that the spiral diopter lens creates several separate points of focus within one lens.1 This structure provides the multifocal effect of a progressive lens, but with minimised distortion, the researchers reported. A spiral diopter lens could function in a contact lens or intraocular implant, and also boasts applications in imaging systems.
The data comes out of 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. Investigator Bertrand Simon, PhD, an associate professor at Institut d’Optique, said the spiral shape has far-reaching implications, particularly for those with age-related farsightedness. “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,” Prof Simon said.
The paper’s first author, Laurent Galinier from SPIRAL SAS in France, explained the lens structure as an “optical vortex,” which causes light to spin. In the news release, he stated the new lens “incorporates the elements necessary to make an optical vortex directly into its surface.”
“Creating optical vortices is a thriving field of research, but our method simplifies the process, marking a significant advancement in the field of optics,” Galinier added.
In Optica, Optica Publishing Group’s journal, the researchers describe the new lens, which they call the spiral diopter. 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.
While developing the lens, the authors noted that image quality appears to be maintained at a satisfactory level with modification of aperture size. In addition, the structure of the optical vortex, and its number and position of focus points, could be changed by adjusting the topological charge, or number of spirals around the centre axis.1 Future trials will document the performance of the spiral diopter lens in real-world conditions, including varying light levels. Further research is expected to illuminate potential applications including prescription eyeglasses, compact imaging systems and wearable devices.