An optical vortex for improved vision

The path followed by this research project is doubly original. First because it began with an application and then moved towards the fundamentals, whereas most research takes the opposite route. Secondly because within it light follows a curious... spiral trajectory.
Let's start again. Laurent Galinier, an optometrist and vision specialist from Bordeaux, designs contact lenses for people with corneal thinning and deformation, as a result of a disease called keratoconus. After many years studying the optical properties of deformations, he was inspired to create new contact lenses with a spiral design, without fully understanding the phenomenon. Somewhat by chance, while selling contact lenses, he met and began collaborating with researchers from Bordeaux's IOGS¹, Bertrand Simon and Jean Augereau from the Photonics, Numerical and Nanosciences Laboratory (LP2N - a CNRS, IOGS and University of Bordeaux unit).

Without knowing that it existed, Laurent Galinier used the optical vortex phenomenon for his lenses, explains Bertrand Simon, adding that this concept has existed in research for 10-15 years. The unique spiral design makes the light rotate, like water in a siphon. This particular behaviour of the light beam enables the lens to provide a clear focus at different distances and in different lighting conditions.

A contact lens with a spiral dioptre

The researchers and the inventor worked together for two years to design this innovative lens, known as the spiral dioptre. Its design and the explanation of the physical phenomena involved are now the subject of a scientific publication in the international journal Optica, co-authored by the researchers and the optometrist.

People suffering from both presbyopia and myopia need progressive contact lenses to see both far and near. But these often suffer from distortions. This is not the case with the contact lens developed by the researchers. "The spiral structure generates several focal zones, enabling clear vision at different distances. What's more, this multifocality is maintained, whatever the ambient luminosity and iris opening, distinguishing our lenses from traditional multifocal lenses," explains Bertrand Simon.

These spiral dioptre lenses could therefore be used for age-related vision problems, cataracts or intraocular lens implants. "In addition to ophthalmology, these new lenses also have the potential to bring about major advances in imaging systems, lighting and mixed reality²." In very practical terms, we could imagine car headlights with more focused lighting or smaller - and lighter - camera lenses, explains the LP2N researcher.

"This research illustrates how an inventor's intuition, combined with a research approach aimed at observing and explaining phenomena, can lead to real scientific innovation," says Bertrand Simon, underlining the importance of interdisciplinary collaboration. The researchers and optometrist Laurent Galinier will shortly be giving concrete expression to this partnership by setting up a LabCom, a joint structure between a research laboratory and a company.
The story is just beginning!

¹ Institut d’optique Graduate School
² which allows virtual objects to be perceived within a real environment