With age, the lens of the eye becomes more rigid, losing its ability to focus objects dynamically, a condition known as presbyopia. The definitive solution for the correction of presbyopia involves replacing the lens with a lens that is capable of mimicking the lens"s function. Now, scientists from the Institute of Optics of the Higher Council for Scientific Research (CSIC), led by researcher Susana Marcos (National Research Award 2019), have developed an intraocular accommodative lens that changes their shape to focus on distant and near objects. The results of this achievement are published in the Optical Journal of the American Optical Society.

“This new lens consists of two elements: a refractive one for the correction of distant vision linked to a deformable element, with haptics (peripheral endings of the lens) that capture the ciliary muscle forces, responsible for changing the shape of the lens to focus, ”explains Marcos. The lens design has been computationally tested, using finite element models, and the manufactured prototype has been evaluated experimentally mounted on a motorized system that emulates the radial forces of the ciliary muscle. The geometric changes in the lens have been characterized by Optical Coherence Tomography (a non-invasive sectional imaging technique), and the power changes by a laser ray tracing system.

According to Andrés de la Hoz, a researcher at the Institute of Optics and first author of the study: "the lens reproduces the behavior of the lens, decreasing its thickness, increasing the equatorial diameter and flattening when uncoupling." The researcher adds that "although there have been previous proposals for accommodative lenses, these have not demonstrated an effective power change, probably because their design does not respond to the natural mechanism of the lens of the eye, or because they depend on the size or integrity of the capsular sac." "Our lens has achieved an effective power change," concludes De la Hoz.

This result is one of the fruits of greater scope of the Presbyopia project, whose principal investigator is Susana Marcos and which is funded by the European Research Council (ERC). Also, this new accommodative lens has received a Proof of Concept project, also from the ERC, to assess its transfer to the market; and has been awarded with a HealthStart project of the Autonomous Community of Madrid (Fundacion Madrid + d) and with a prestigious CaixaImpulse Project.