Monthly Archives: September 2015

Experimental sound-induced corneal vibrational modes by OCT, published in Biomedical Optics Express

Sin título


We report mechanical resonance vibrational modes of the cornea induced by sound waves using phase sensitive OCT. A dynamic finite element model predicts the observed three cornea resonance frequency modes in a frequency range between 50-400 Hz in bovine eyes. The work is a collaboration between Yun’s Lab (Wellman Center of Photomedicine/ Mass General Hospital/Harvard Medical School) and VioBio Lab (Instituto de Optica, CSIC).

Full reference:  Akca BI, Chang EW, Kling S, Ramier A, Scarcelli S, Marcos S, Yun SH. Observation of corneal vibrational resonance by optical coherence tomography. Biomedical Optics Express 2015;6:3314-3319

High participation of VioBio at IONS Valencia, Optical Society of America











The next IONS, a conference of the International Network of students in Optics, sponsored by the Optical Society of America, will take place in Valencia Sept 24-26. The meeting has been organized by Student Chapters in Spain, including IOSA, the Student Chapter of the Institute of Optics, CSIC, Madrid, where VioBio members have great involvement.

These are VioBio Lab contributions to the meeting:

-Susana Marcos will give the following keynote presentation: “Light and Optics to improve vision” at Conference Room. Sala d’Actes (09:00 am), Friday, 25 September.

-Maria Vinas is a member of the organizing committee and presider of session: Student Talks. Session T2–Visual Optics at Conference Room. Sala d’Actes (10:00 am), Friday, 25 September.

-Clara Benedí will be in the Student Talks. Session T2 –Visual Optics, Conference Room. Sala d’Actes (10:00 am) talking about “Comparison between model and realistic eyes with through-focus intraocular lens”. Friday, 25 September.

-Aiswaryah Radhakrishnan is going to talk about “Hand-Held Vision simulator for evaluating eisual performance of presbyopia corrections” at Student Talks. Session T2 –Visual Optics, Conference Room. Sala d’Actes (10:00 am). Friday, 25 September.
-Mengchan Sun presents her poster “OCT-based ray tracing on pseudophakic eyes to identify optimal IOL centration” at Poster Room. Aula 0.1 (11:00 am). Friday, 25 September.

A link to the program can be found here:


Phase unwrapping with a virtual Hartmann-Shack wavefront sensor




A virtual Hartmann-Shack wavefront sensor as a phase unwrapping tool was demonstrated in a digital phase-shifting point diffraction interferometer and the method was compared with the Fourier unwrapper.

Full publication: Vyas Akondi, Claas Falldorf, Susana Marcos, and Brian Vohnsen. OSA Vol.23, issue 20, pp. 25425-25439 (2015)


Keywords: adaptive optics, wavefront sensing, interferometry, phase measurement and noise

Susana Marcos wins the Alcon Research Institute Award

Sin título


Susana Marcos joins a group of select scientists whom the Alcon Research Institute (ARI) regards as “outstanding, internationally recognized experts at the cutting edge of their respective field of vision research.” Eye care company Alcon, Inc., created ARI and the Alcon Award in 1981 to foster basic and clinical research for ocular diseases. Awardees are chosen by a scientific selection committee comprising of elite members from the eye research community.
The Awards were presented last weekend at Mass Eye and Ear /Harvard University Boston during the Alcon Research Institute Symposium. Susana Marcos said to to be “honored to become part of the ARI selected community”.

Enrique Gambra’s PhD public defense: “Accommodation: Optical function and crystalline lens imaging”



Enrique Gambra will defend his thesis entitled “Accommodation: Optical function and crystalline lens imaging” next September 30 (11:30) at the School of Medicine, University of Valladolid.

The event can be followed by streaming, through this Link

New Logo for VioBio Lab


VioBio Lab launches its new logo.

Check for it in presentations, posters and materials presenting research develeoped in our lab.

Effect of surface astigmatism and GRIN on lens astigmatism, published in IOVS


We estimated the contribution of the gradient refractive index (GRIN) and lens surfaces to lens astigmatism and lens astigmatic angle as a function of age in human donor lenses. The axis of lens astigmatism is close to the astigmatic axis of the anterior lens surface. Age-related changes in lens astigmatism appear to be related to changes in the anterior lens astigmatism. The influence of the GRIN on lens astigmatism and the astigmatic axis is minor.

Full publication: Astigmatism of the Ex Vivo Human Lens Surface and Gradient Refractive Index Age Dependent Contributions, IOVS –  August 2015 –  Vol. 56 – No. 9 – 5070 . J. Birkenfeld , A. de Castro, S. Marcos

Ample coverage on Spanish media on VioBio Lab work on presbyopia



Following recent conferences, the media have featured interviews and articles on our laboratory work on presbyopia, in the context of ERC grant presbyopia. The following links contain some recent media coverage:


Local press: Gaceta Regional Salamanca – 1 Sep

Local press: Gaceta Regional Salamanca – 2 Sep – 2015Use SHIFT+ENTER to open the menu (new window).

DCYIT press: Agencia Iberoamericana para la difusión de la ciencia y la tecnologíaUse SHIFT+ENTER to open the menu (new window).

Cadena SER: Interview

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