Material Properties from Air Puff Corneal Deformation in model and porcine corneas, published in PLOS One

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Fig. 1.Model cornea (MC). A. Model cornea made out of hydrophilic contact lens material. B. Model cornea mounted in artificial eye chamber.



Fig. 6. FE model of the model eye with the applied boundary conditions.
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Fig 10. Stress-strain curves of the MC materials and porcine corneas by the inverse modeling from air-puff measurements and from uniaxial extensiometry measurements. C: Material Q

We used model polymer corneas of different materials and thicknesses and porcine corneas ex vivo (at constant intraocular pressure) to validate an inverse optimization approach to retrieve material properties from air puff corneal deformation imaging. Material properties were compared with those obtained from uniaxial extensiometry revealing high similarity.  In polymer artificial corneas material properties were retrieved independent on corneal thickness. The study demonstrates that the combination of air puff corneal deformation imaging with inverse modeling is a reliable non-invasive technique to estimate corneal mechanical properties. The study has just been published in PLOSOne.
Full reference: Bekesi N, Dorronsoro C, de la Hoz A, Marcos S (2016) Material Properties from Air Puff Corneal Deformation by Numerical Simulations on Model Corneas. PLoS ONE 11(10): e0165669. doi:10.1371/journal.pone.0165669

Link to publication.

Link to CSIC Press Release

Susana Marcos receives major honor from the Spanish Scientists Association

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Prof. Marcos receives the “Placa de Honor” from Asociacion Española de Cientificos, the maximum distinction given by the Society, for her research in the “physics  and the mechanisms of the vision process, diagnostics and treatment of ocular conditions,  for her international scientific achievements  and for her technology transfer activity during her career”.  The award was presented at the annual event of the association.
Full program of the event.
Presentation of Prof. Marcos by Director of the Institute of Optics, CSIC (Dr. Juan Diego Ania).
Response of Prof. Marcos.

Susana Marcos, selected one more year among the most influencial women




The magazine Yo Dona has selected the 500 most influencial women in the country in all fields, and listed Prof Susana Marcos among the top scientists.

You can read the full list here.

Spin-off company 2EyesVision present in MIT Entrerprise Forum and in XXII Foro de Inversion Madrid+d


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2EyesVision has been selected to participate in two of the major investment forums in Madrid: MIT Entreprise Forum and Foro de Inversion Madrid+d, and created excitement on the SimVis technhology developed at VioBio_Lab. Business Developer Alvaro Sanchez-Lozano, working in the context of ERC Proof-of-Concept SimVisSim Project, presented in both events.

New in the lab: Sally McFadden


Prof. Sally McFadden (University of Newcastle, New South Wales, Australia), on sabbatical last year at VioBio Lab is visiting again this year, for collaborative work on myopia development. Welcome back!

New in the Lab: Juan Luis Méndez


We welcome predoctoral Fellow Juan Luis Méndez to VioBio Lab, where he will be undertake collaborative work with spin-off company 2Eyes Vision.  Juan Luis Mendez holds a degree in Medicine from the University of La Laguna and a Masters in Optical Technologies from Universidad Complutense de Madrid. He has relocated from Germany, where he was working as a Technical Assistant for the “Early diagnosis of mouth and oropharynx cancerous lesions means hyperspectral imaging” research project at the “Universitätsklinikum Bonn” teaching Hospital. He has received an Industrial Doctorate Fellowship from the Spanish Government to work on clinical and technical aspects of SimVis.

New in the lab: Ashik Mohammed


We welcome Ashik Mohamed, a principal investigator in L V Prasad Eye Institute, Hyderabad, India, who will be visiting VioBio Lab in the context of a CSIC iCoop Cooperative Project.  
Ashik holds a degree in Medicine, and a Masters in Medical Biotechnology
from Indian Institute of Technology, Madras.  
Ashik shares interests with VioBio Lab on crystalline lens properties, aging  and accommodation.


Job Offers: Two open positions for Electro-optical Engineers at VioBio Lab


Positions for Electro-optical Engineers (one expert in Software and Firmware automation of opto-electronic and opto-mechanic elements in laboratory set-ups and one expert in setting-up of biomedical systems through opto-electronic instruments) are open at VIOBIO Lab, with immediate availability, in the context of regional funding for supporting laboratories and research centres in the Region of Madrid.

See full profiles and contact details in the corresponding job offers:

Electro-optical Engineer post-1

Electro-optical Engineer post-2


VioBio Lab at Frontiers in Optics 2016, Optical Society, Rochester NY


VioBio Lab Members have participated extensively at the OSA Frontiers in Optics 2016, which has showcasted an excellent scientific program as well as extraordinary OSA centennial celebrations.

The following papers were presented at the scientific program:

Vyas Akondi, Carlos Dorronsoro, Enrique Gambra, Maria Vinas, Daniel Pascual, Sara Aissati, Susana Marcos; Temporal multiplexing and simulation of multifocal intraocular lenses. Contributed oral in “Novel Design Concepts for Eye Correction and Vision Simulators I” sesión

Andres De La Hoz, Eduardo Martinez-Enriquez, Carlos Dorronsoro, Nandor Bekesi, Nicolas Alejandre, Hrebesh Subhash , Daniel Pascual, Susana Marcos; Surface-changing Accommodating Intraocular Lens for Presbyopia Correction. Contributed oral in “Novel Design Concepts for Eye Correction and Vision Simulators II” sesión

Carlos Dorronsoro, Aiswaryah Radhakrishnan1, Jose Ramon Alonso-Sanz, Daniel Pascual, Enrique Gambra, Vyas Akondi, Susana Marcos;  SimVis: See-through Simulation of Presbyopic Corrections. Contributed oral in “Novel Design Concepts for Eye Correction and Vision Simulators II”

Susana Marcos, Pablo Perez-Merino, Miriam Velasco-Ocana1, Eduardo Martinez- Enriquez, Luis Revuelta, Sally A. McFadden; Changes in anterior segment 3-D geometry in normal and myopic guinea pig eye. Contributed oral in “Understanding  Myopia Development”

In Addition:

Susana Marcos was a panelist at the Global Women of Light Symposium, WISTII, in the panel presider.

Andres de la Hoz, President of the IOSA Student Chapter attended the Student leadership Conference.


At the OSA Editor’s reception on 17th October, Vyas Akondi was recognized as 2016 OSA Outstanding Reviewer.

Representing the Optical metrology Technical Group as a committee member, Vyas Akondi attended the 2016 Technical Group Leadership Meeting on 17th October.

Presider of a technical session titled: Novel Design Concepts for Eye Correction and Vision Simulators II on 19th October.

Oral presentation by Vyas Akondi on 19th October – Title of the talk – “Temporal multiplexing and simulation of multifocal intraocular lenses”, Authors: Vyas Akondi, Carlos Dorronsoro, Enrique Gambra, Maria Vinas, Daniel Pascual, Sara Aissati, and Susana Marcos, Frontiers in Optics 2016, OSA Technical Digest (online) (Optical Society of America, 2016), paper FW2A.3.

Susana Marcos chaired the Vision and Color Subcommittee, organizing 5 sessions and one symposium, presided the Symposium on 100 Years of Vision at OSA: Most cited vision papers in OSA journals
Susana Marcos presented at the Plenary session as elected Frontiers in Optics 2017 Co-chair
Carlos Dorronsoro, Vyas  Akondi and Susana Marcos attended the OSA Fall Vision Meeting
And of course attended the amazing centennial celebration events held during the week. A productive and memorable conference!

Noise robust phase unwrapping with a virtual pyramid


Now, it is possible to effectively unwrap phase with noisy and low-signal interferometric measurements with the new method of phase unwrapping called the virtual pyramid wavefront sensor. This was demonstrated while reconstructing wavefronts from interferograms obtained in a digital (SLM-based) phase-shifting point diffraction interferometer. In comparison with existing methods, this new phase unwrapping method was found to be robust to random noise. We believe that this method can be applied to several metrology applications in ophthalmology, magnetic elastography and astronomy.

Full Citation: Vyas Akondi, Brian Vohnsen, and Susana Marcos, “Virtual pyramid wavefront sensor for phase unwrapping,” Applied Optics 55(29), 8363-8367 (2016).

Full Article:


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