Perceptual impact of astigmatism induction in presbyopes, published in Vision Research

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Using an Adaptive Optics system, we investigated the effect of induced astigmatism on subjective best focus and on visual acuity in subjects of different ages (pre-presbyopic and presbyopic) and with different refractive profiles (emmetropes and astigmats). The custom-developed Adaptive Optics system allowed correction of high order aberrations and induction of astigmatism. The article published in Vision Research shows that the findings may be connected to long term exposure to astigmatism in astigmats and corrected presbyopes.

Full reference: Clara Benedi-Garcia, Miriam Velasco-Ocana, Carlos Dorronsoro, Daniel Pascual, Martha Hernandez, Gildas Marin, Susana Marcos, “Perceptual impact of astigmatism induction in presbyopes”, Vision Research 165, 143-151 (2019). 

Full article here.

New in the lab: Amal Zaytouny


We welcome Amal Zaytouny who joins VioBio Lab and 2EyesVision under the Industrial Doctorate Program funded by Madrid Regional Government. The program aims at strengthening the competitiveness of Madrid companies by promoting collaboration and knowledge transfer between the academic world and the business world.

Amal holds a BSc in Optics and Optometry and MSc in Optometry and Vision Science from Universidad Politécnica de Catalunya. She has previous experience in the clinical area (Hospital de la Santa Creu i Sant Pau, Barcelona) and has performed an internship in the Medical Department of Alcon, where she worked in the field of intraocular and contact lenses, as well as in refractive surgery. 

VioBio Lab and 2EyesVision celebrate South Summit Award and new office space


2EyesVision, spin-off company of the Visual Optics and Biophotonics Lab (CSIC), was selected, among more than 3.5 thousand start-ups, as the winner of the Healthcare and Biotech category of the South Summit 2019, the leading meeting on entrepreneurship and innovation that brings together startups, corporations and investors, organized by South Summit-Spain Startup, powered by IE University and co-organized by the Madrid City Council in collaboration with BBVA, Endesa, Wayra, Sabadell and Google. During the event 2EyesVision was also selected as one of the 10 most innovative start-up companies in Spain. 

To celebrate this recognition and the relocation of the company’s offices, 2EyesVision  held yesterday an event in the new space located in Tres Cantos (Madrid) attended by the staff, partners and investors of the spin-off company.

Check 2Eyes Vision pitch for the South Summit 2019 finals here

More information about the award in the following links:


Morphological changes of the human crystalline lens in myopia, published in Biomedical Optics Express


Custom quantitative 3-D OCT has been used to image the full crystalline lens in vivo in young myopes. We found that with myopia (and increased axial length) lens thins, equatorial, and capsular stretch while keeping constant volume. Axial elongation appears counteracted by a crystalline lens power reduction, while corneal power remains unaffected.

Full reference: Geethika Muralidharan, Eduardo Martínez-Enríquez, Judith Birkenfeld, Miriam Velasco-Ocana, Pablo Pérez-Merino and Susana Marcos, “Morphological changes of human crystalline lens in myopia,” Biomed. Opt. Express 10, 6084-6095 (2019)

Full article here

Pre-operative simulation of post-operative multifocal vision published in Biomedical Optics Express


While multifocal intraocular lenses are increasingly implanted to correct for presbyopia, how one sees with a multifocal correction is hard to explain and imagine. The current study evaluates the quality of various visual simulating technologies by comparing vision with simulated MIOLs pre-operatively and the implanted MIOLs post-operatively in the same patients. Two simulation platforms were used: a custom-developed Adaptive Optics system, with two visual simulator devices: a spatial light modulator (SLM) and an optotunable lens operating under temporal multiplexing (SimVis); and the wearable, binocular, large field of view clinical simulator SimVis Gekko developed by CSIC spin-off company 2Eyes Vision. All devices were programmed to simulate a trifocal diffractive MIOL (POD F, FineVision, PhysIOL). Through-focus decimal visual acuity was measured in eight patients pre-operatively simulating the trifocal lens and post-operatively with implantation of the same MIOL. The article published in Biomedical Optics Express shows that visual simulations are useful programmable tools to predict visual performance with MIOLs, both in an Adaptive Optics environment and in a clinical simulators, since pre-operative visual simulations and post-operative data are in good agreement.

Full reference: Maria Vinas, Sara Aissati, Mercedes Romero, Clara Benedi-Garcia, Nuria Garzon, Francisco Poyales, Carlos Dorronsoro, and Susana Marcos, “Pre-operative simulation of post-operative multifocal vision,” Biomed. Opt. Express 10, 5801-5817 (2019).

Full article here

Susana Marcos received Ramón y Cajal Medal at the Spanish Royal Academy of Science

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Ramón y Cajal Medal Award Ceremony took place at the Spanish Royal Academy of Science on October 23rd in an event presided by the President of the Academy D. Jesús María Sanz, Secretary of State Ángeles Heras and CSIC President Rosa Menéndez. 

The Ramón y Cajal Medal highlights the work of Spanish scientists under 50. The jury of the award pointed that Prof. Marcos has maintained an outstanding scientific career at an international level, with a fully multidisciplinary research program to understand the basic mechanisms of human vision, develop diagnostic tools in ophthalmology and to invent new optical solutions for the correction of the most common vision problems. 

More information: Real Academia de Ciencias Exactas, Físicas y Naturales

Monovision and the Misperception of Motion published in Current Biology


Monovision is a common prescription lens correction for presbyopia. Each eye is corrected for a different distance, causing one image to be blurrier than the other. Millions of people have monovision corrections, but little is known about how interocular blur differences affect motion perception. In a paper published in Current Biology, we report that blur differences cause a motion illusion that makes people dramatically misperceive the distance and three-dimensional direction of moving objects. The effect occurs because the blurry and sharp images are processed at different speeds. For moving objects, the mismatch in processing speed causes a neural disparity, which results in the misperceptions. The results show that these misperceptions can be severe enough to impact public safety and demonstrate that they can be eliminated with novel combinations of non-invasive ophthalmic interventions. The motion illusion and the paradigm we use to measure it should help reveal how optical and image properties impact temporal processing, an important but understudied issue in vision and visual neuroscience.

Full reference: Johannes Burge, Victor Rodriguez-Lopez, Carlos Dorronsoro. “Monovision and the Misperception of Motion”, Current Biology 29, 1–7 (2019)

Full article here

Presenting LightLens, a CaixaImpulse project


CaixaImpulse presents the LightLens project, a tech transfer venture of an accommodating intraocular lens developed by the Visual Optics and Biophotonics Lab. The concept, prototype and demonstration of an intraocular lens capable of dynamically reshape is the result of the European Research Council Advanced Grant PRESBYOPIA. This new project promotes its next steps into commercialization.

Watch the video presenting the CaixaImpulse project here

More information about the project here


New in the lab: Miguel Eckstein

Miguel Eckstein

We welcome Dr. Miguel Eckstein (Professor, Psychological and Brain Sciences & Electrical and Computer Engineering, University of California, Santa Barbara) to VioBio Lab. He is now spending his sabbatical with us funded by a Guggenheim Foundation Fellowship. 

He received a BSc in Physics & Psychology at UC Berkeley and PhD in Cognitive Psychology at UCLA. He worked at the Department of Medical Physics and Imaging, Cedars Sinai Medical Center and NASA Ames Research Center before joining UC Santa Barbara. Dr. Eckstein uses computational modeling, functional magnetic imaging (fMRI), electro-encephalography (EEG), eye tracking and psychophysics to understand the brain processes mediating perception, attention and learning. He uses the basic knowledge he acquires about visual processing to work with engineers on applied problems including medical imaging, computer vision and human/computer interaction. He is exploring collaborative projects with VioBio Lab on children recovering from congenital blindness as well as assessment of corrective optical solutions with task-based performance metrics.

New in the lab: Lupe Villegas


Lupe Villegas, BSc in Physics from Escuela Politécnica Nacional de Ecuador, has recently joined VioBio Lab with a FPI Predoctoral Grant awarded by the Spanish Ministry of Science. She will undertake her thesis research work on myopia and new optical technologies.

Lupe holds a MSc in Biomedical Engineering from Paris Descartes University and a MSc in Biophysics from Universidad Autónoma de Madrid. She has worked in preclinical studies in Magnetic Resonance Imaging and Optical Imaging at Ecole Nationale Superieure de Chimie de Paris and she did her master thesis in Madrid in Macromolecules Structure Department at CNB (National Biotechnology Center, CSIC). 

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