Colloquia & Guest Speakers
The Gradient Refractive Index of the Eye's Crystalline Lens
Alberto de Castro, Research Scientist, Instituto de Óptica "Daza de Valdés", CSIC
Monday, February 9, 2026
3:30 p.m.
Presented in Goergen 101 on Zoom only
Abstract
Among all ocular components, the crystalline lens undergoes the most substantial changes with age. The lens features a gradient refractive index (GRIN) with higher refractive index in the nucleus that progressively decreases toward the cortex in all directions. This GRIN structure plays a fundamental role in ocular optics by enhancing the lens focusing power and contributing to the negative spherical aberration typical in young lenses, which counterbalances the positive spherical aberration of the cornea. The Colloquium will review research efforts aiming at reconstructing the GRIN distribution with optical methods, in particular Optical Coherence Tomography, which allow subject-specific characterization of the lens's refractive index structure.
Biography
Alberto de Castro is a researcher at the Instituto de Óptica “Daza de Valdés” (CSIC) in Madrid, interested on applying biomedical imaging and optical technologies to investigate the human eye, in particular human crystalline lens optics. He has contributed to the development of individualized methods for characterizing ocular optics and for studying how the lens changes with age and accommodation. His research combines the development of optical instrumentation and optical modelling to study human vision.