Visual Optics & Psychophysics
The Visual Optics and Psychophysics Laboratory was established in 2009 and has 3 major themes of research: To understand the impact of distortions in the eye on the perception of form and depth vision; how the visual system adapts to such optical distortions over time; develop instrumentation and technology for non-invasive measurement of the refractive power of the eye.
The lab uses human disease and iatrogenesis models for studying these focal themes. Non-invasive measurements of wavefront aberrometery, psychophysics and computational reconstruction of image quality are performed on patients with corneal disease like keratoconus and cataract and surgical procedures like corneal transplants, refractive surgery to understand the distortions experienced in the eye and their perception of form and depth vision.
The Optics of Vision
In verse 4.081 of the Thevaram, Saint Thirnāvukasarar describes the Nataraja statue in the Chidhambaran temple of Thanjavur district, Tamil Nadu, through the following passage:
“…kuniththa puruvamum, kovvaich chevvaayin kumin sirippum, paniththa jadayum pavazham pol meniyil paal vennirumum, iniththamudaiya eduththa porpaathamum kaanappetraal, maanitha piraviyum venduvathe intha maa nilaththe.”
This roughly translates to “If one can witness the curved eyebrows, the budding smile in the ruddy mouth resembling the kovai fruit, the matted locks kept wet by the river Ganga, the coral colored body smeared with milky white sacred ash, and the raised holy foot of lord Shiva, it is highly desirable to take birth in this world as a human being.” [1]
Such a poetic description of the Nataraja is experienced only through the resolution of fine spatial details, as seen in the left image panel shown above. Once blurred (see middle and right panels), all these details are obliterated, leaving only the gross form of Nataraja visible. [2]
Our lab studies how such blurred imagery is processed by the human visual system, what limitations to sensory-motor processing does it impose and how the visual system adapts to prolonged experience of such degraded imagery.
[2] Image courtesy: Fourier Optics Calculator developed by Prof Larry Thibos of the Indiana University School of Optometry. The left panel is the original image, the middle panel is blurred with 0.5microns of defocus and the right panel is blurred with 0.5microns of coma and trefoil, all over 5mm pupil diameter.
Principle investigators
Shrikant Bharadwaj
Dr Shrikant Bharadwaj uses a combination of experimental, behavioral and computational techniques to address this research agenda. His laboratory actively publishes research work in international peer-reviewed vision science journals and the research work is generously supported by extramural grants from the Government of India and the optical industry.
Dr Bharadwaj serves as the Network Associate Director of the Brien Holden Institute of Optometry and Vision Sciences at LVPEI. He is also actively involved in teaching undergraduate and postgraduate students of optometry at the L V Prasad Eye Institute.
Publications
Support Research
The functioning eye is a mystery that is slowly unravelling under the scientific gaze. Help us make it possible to understand the eye.
Preetirupa Devi
Tai Jarkum
Indrani Sirivella
Sofiya Muskan
Pudi Bhanu Swaroop
Erum Nisha
Sanidhya Jain
Marylina Debbarma
Lab Members in the past
- Preetam Kumar – Post-doctoral research fellow, University of Houston College of Optometry, Houston, USA.
- Bhagya Lakshmi Marella – Post-doctoral research fellow, Indiana University School of Optometry, Bloomington, USA
- Praveen Kumar Bandela – Post-doctoral research fellow, nthalmic Pvt Ltd, Sydney, Australia
- C Vijay Reena Durai – Research associate, Bionic eye centre, Randwick, Australia
- Vinay Kumar Nilagiri – Post-doctoral research fellow at University of Western Australia, Perth, Australia
- Chandrika Ravisankar – PhD student at SRM Institute of Science and Technology, Chennai, India
- Samrat Sarkar – PhD student at University of New South Wales, Sydney, Australia
- Nakka Geetha Sravani – PhD student at University of New South Wales, Sydney, Australia
- Asra Fatima – PhD student at University of Hyderabad School of Medical Sciences, Hyderabad, India
- Veerendranath Pesala – Consultant Optometrist, L V Prasad Eye Institute, Hyderabad, India
- Sabyasachi Goswami – PhD student at the Department of Brain and Cognitive Sciences – University of Rochester
- Ketakee Jain, Faculty, Vinayaka Mission Research Foundation, Salem, India
- Mohammed Abdul Subhan
- Naveen Kumar
- Swaathi Balaji
- Avina Patel
