Shrikant A. Bharadwaj, BSOpt., Ph.D

Shrikant A. Bharadwaj BSOpt., PhD
Scientist and Associate Director of Optometry
L V Prasad Eye Institute
Hyderabad Eye Research Foundation, Hyderabad, INDIA
Email:bharadwaj [at] lvpei [dot] org

Research | Resume | Family

Research

SRB in Cliff's lab...

Human ocular accommodation (the auto-focus mechanism of the human eye)is achieved primarily by a change in the power of lens inside the eye. The change in the lens power is brought about the constriction of the ciliary muscle in response to parasympathetic innervation sent the brain. As we age, our accommodative ability progressively deteriorates primarily due to the inability of the lens to change shape. The progressive deterioration in the focusing ability with aging is termed as "presbyopia". While we have a fairly good understanding of the different bio-mechanical structures involved in accommodation and how their properties change with age, our knowledge of the neural control of accommodation is still limited. As a graduate student, I investigated various aspects of the neural control of accommodation and how the neural control changed with age. A second-order feedback control model of accommodation was developed based on the static and dynamic characteristics of accommodation and based on already observed neural firing patterns that are related to accommodation responses. Through these empirical and modeling exercises, I realized that the accommodative system in humans does not work with machine-like properties but it adopts different control strategies in order to optimize different response characteristics. These control strategies are likely to change with viewing conditions, practice and with age.

We have also developed a web-based model of accommodation that simulates the performance of the accommodative control system when the biological lens is replaced by a prosthetic intraocularlens material. Please visit Schor Lab and click on "A-IOL Model" to interactively work with this model.

SRB in Rowan's lab...

Another important aspect of accommodation that has not been investigated extensively is its development. By about three months of age, infants start accommodating to targets that are placed at different distances in front of them. The link between accommodation and convergence eye movements has also been shown to present by this age. While the cross-link between accommodation and convergence eye movements has been well studied in adults, very little is known about their interaction in infants and toddlers. As a post doctoral fellow, I have started investigating two specific aspects of this cross-link interaction. One, how does the cross-link interaction change with the growth of the eye ball and the head and second, how does the cross-link interaction functions when the infant moves its eyes to an eccentric position of gaze? We have made theoretical predictions on the expected change in the cross-link gains in order to have optimal performance of both the accommodative and the convergence control systems. We have also started comparing these predictions with empirical measurements of the cross-link gains in infants, toddlers and pre-schoolers.

Other research interests include...

Sensory-motor processing of defocus & disparity
Neural control of oculomotor systems
Neural adaptation to blur
Emmetropization and Myopia progression

Resume

Academic qualifications

2011 - : Associate Director of Optometry, L V Prasad Eye Institute (LVPEI), Hyderabad, India
2009 - : Scientist & Associate Professor of Optometry, L V Prasad Eye Institute (LVPEI), Hyderabad, India
2006 - 2009: Post-doctoral fellow in Vision Science, Indiana University, Bloomington, USA
2001 - 2005: Doctor of Philosophy (PhD) in Vision Science, University of California, Berkeley, USA
1997 - 2001: Bachelor of Science (BS Opt) in Optometry, Elite School of Optometry, BITS, India

Awards & honors

2010 - 2014: Ramalingaswami fellowship from the Department of Bio-Technology (DBT), Govt of India.
2009: Travel grant for the 3rd Annual Berkeley Conference on Translational Research, UC Berkeley.
2009: Santen Pharmaceuticals travel grant for ARVO conference.
2008 - 2009: Fight For Sight post-doctoral fellow.
2006 - 2007: Elsevier award for top 50 reviewers for Vision Research journal.
2006: Phi Beta Kappa nomination, UC Berkeley.
2004: Institute fellow for academic and professional development, UC Berkeley.
2003 & 2005: Vistakon travel fellowship for ARVO.
2003: University Regents fellowship.
2002: Outstanding graduate teaching assistant award.
2001 - 2002: University block grant fellowship.

Theses

PhD in Vision Science: Neural control strategies of the human ocular accommodation.
BS in Optometry: A comparison of the lag of accommodation in myopes under spectacle and contact lens wearing conditions.

Peer-reviewed publications

Bharadwaj, S. R., Wang, J., & Candy, T. R. (2011). Pupil responses to near visual demand during human visual development. Journal of Vision. In Press.
Bharadwaj, S. R., & Candy, T. R. (2011). The effect of lens-induced anisometropia on accommodation and vergence during human visual development. Investigative Ophthalmology & Visual Science. In Press.. Journal of Vision, 9, 1 � 18.
Bharadwaj, S. R., & Candy, T. R. (2009). Accommodative and vergence responses to conflicting blur and disparity cues during visual development. Journal of Vision, 9, 1 � 18.
Bharadwaj, S. R., Vedamurthy, I., & Schor, C. M. (2009). Short-term adaptive modification of dynamic ocular accommodation. Investigative Ophthalmology & Visual Science, 50, 7, 3520 - 3528.
Bharadwaj, S. R., & Candy, T. R. (2008). Cues for the control of ocular accommodation and vergence during postnatal human development. Journal of Vision, 8, 14, 1 - 16.
Schor, C. M., & Bharadwaj, S. R. (2008). Adaptive calibration of dynamic accommodation - implications for accommodating intraocular lenses. Journal of Refractive Surgery, 24, 984 - 990.
Rymer, J., Choh, V., Bharadwaj, S. R., Padmanabhan, V., Modilevsky, L., Jovanovich, E., Yeh, B., Zhang, Z., Guan, H., Payne, W., & Wildsoet, C. F. (2007). The albino chick as a model for studying ocular developmental anomalies, including refractive errors, associated with albinism. Experimental Eye Research, 85, 431 - 442.
Candy, T. R., & Bharadwaj, S. R. (2007). The stability of steady-state accommodation in human infants. Journal of Vision, 7, 1 - 16.
Bharadwaj, S. R., Hoenig, M. P., Sivaramakrishnan, C. V., Karthikeyan, B., Simonian, D., Mau, K., Rastani, S., & Schor, C. M. (2007). Variation of binocular-vertical fusion amplitude with convergence. Investigative Ophthalmology & Visual Science, 48, 1592 - 1600.
Schor, C. M., Bharadwaj, S. R., & Burns, C. D. (2006). Dynamic performance of acccommodating intraocular lenses in a negative feedback control system: A simulation based study. Computers in Biology and medicine, 37, 1020 - 1035.
Bharadwaj, S. R., & Schor, C. M. (2006). Initial destination of the disaccommodation step response. Vision Research, 46, 1959 - 1972.
Schor, C. M., & Bharadwaj, S. R. (2006). Pulse-step models of control strategies for dynamic ocular accommodation and disaccommodation. Vision Research, 46, 242 - 258.
Bharadwaj, S. R.,& Schor, C. M. (2006). Dynamic control of ocular disaccommodation I. First- and second-order dynamics. Vision Research, 46, 1019 - 1037.
Bharadwaj, S. R., & Schor, C. M. (2005). Acceleration characteristics of human ocular accommodation. Vision Research, 45, 17 - 28.
Schor, C. M., & Bharadwaj, S. R. (2005). A Pulse-Step model of accommodation dynamics in the aging eye. Vision Research, 45, 1237 - 1254.
Schor, C. M., & Bharadwaj, S. R.(2004). A Pulse-Step model of accommodation dynamics. Conference Proceedings of the IEEE Engineering in Medicine & Biology Society, 1, 766 - 769.
Webster, M. A., Webster, S. M., Bharadwaj, S. R., Verma, R., Jaikumar, J., Madan, G., & Vaithilingam, E. (2002). Variations in normal color vision. III. Unique hues in Indian and United States observers. Journal of Optical Society of America, 19, 1951 - 1962.
Webster, M. A., Webster, S. M., MacDonald, J., & Bharadwaj, S. R. (2001). Adaptation to blur. Proceedings of the SPIE: Human Vision and Electronic Imaging, 4299, 69 ?78.

Selected conference presentations

Pesala, V., Srinivasan, S., Solomon, E., Pamplona, V., Oliviera, M., Raskar, R., & Bharadwaj, S.R. (2001). Comparison of a novel cell phone-based refraction technique (NETRA) with objective clinical retinoscopy. ARVO, Ft. Lauderdale, USA.
Bharadwaj, S. R., Raghuram, V., & Labishetty, V. (2011). Impact of induced anisometropia on accommodative responses to step and ramp stimuli. ARVO, Ft. Lauderdale, USA.
Bharadwaj, S. R., Sravani, G., Narasaiah, A., Raghuram, V., Haggerty, K., & Candy, T. R. (2011). Inter- and intra-subject variability of luminance-slope calibration in eccentric photorefraction. Asia-ARVO, Sentosa, Singapore.
Bharadwaj, S. R. (2010). Neural control of ocular accommodation. Elite School International Conference on Optometry and Vision Science (EIVOC), Chennai, India.
Bharadwaj, S. R., & Candy, T. R. (2010). Characteristics of pupil responses during human visual development. ARVO, Ft. Lauderdale, USA.
Bharadwaj, S. R., & Candy, T. R. (2009). The effect of induced anisometropia on accommodation and vergence during development. 3rd annual Berkeley conference on translational research, Berkeley, USA.
Bharadwaj, S. R., & Candy, T. R. (2009). Accommodation and vergence responses to conflicting blur and disparity cues during visual development. ARVO, Ft. Lauderdale, USA.
Teel, D. F. Bharadwaj, S. R., & Candy, T. R. (2009). Accommodative-vergence and vergence-accommodation cross-link gains in pre-schoolers. ARVO, Ft. Lauderdale, USA.
Bharadwaj, S. R., (2008). Cues for the control of accommodation and vergence during postnatal human development. University of Waterloo School of Optometry, Ontario, Canada.
Bharadwaj, S. R., & Candy, T. R. (2008). Accommodation and vergence responses to conflicting blur and disparity cues in the developing visual system. VSS, Naples, USA.
Bharadwaj, S. R., & Candy, T. R. (2008). Cues for the control of accommodation and vergence during postnatal human development. ARVO, Ft. Lauderdale, USA.
Bharadwaj, S. R., Crow, J., Nance, J., & Candy, T. R. (2007). Effect of cycloplegia on the microfluctuations of steady-state ocular accommodation. ARVO, Ft. Lauderdale, USA.
Wang, J., Bharadwaj, S. R., & Candy, T. R. (2007). The monocular threshold stimulus for accommodation in human infants. ARVO, Ft. Lauderdale, USA.
Bharadwaj, S. R., & Candy, T. R. (2006). Variation of steady-state accommodation with viewing distance in infants. AAO, Denver, USA.
Bharadwaj, S. R., Su, Y., & Schor, C. M. (2006). Short-term adaptive modification of dynamic ocular accommodation. ARVO, Ft. Lauderdale, USA.
Kim, Y. S., Bharadwaj, S. R., & Schor, C. M. (2006). Effect of altering dark focus of accommodation on the dynamics of disaccommodation. ARVO, Ft. Lauderdale, USA.
Schor, C. M., Bharadwaj, S. R., Burns, C. D. (2006). Dynamic performance of accommodating-intraocular lenses: A simulation-based study. ARVO, Ft. Lauderdale, USA.
Hoenig, P., Bharadwaj, S. R., Simonian, D., Mau, K., Rastani, S., Breen, L., & Schor, C. M. (2006). Variation of vertical fusional vergence amplitude with horizontal vergence. ARVO, Ft. Lauderdale, USA.
Bharadwaj, S. R., Kim, Y. S., & Schor, C. M. (2005). Dynamic control of ocular disaccommodation. ARVO, Ft. Lauderdale, USA.
Schor, C. M., & Bharadwaj, S. R. (2005). A Pulse-Step model of ocular disaccommodation. VSS, Sarasota, USA.
Sivaramakrishnan, C. V., Karthikeyan, B., & Bharadwaj, S. R. (2005). Influence of convergence on vertical fusional vergence amplitude. Singapore Eye Research Institute (SERI)-ARVO, Singapore.
Bharadwaj, S. R., & Schor, C. M. (2004). A Pulse-Step model of accommodation dynamics. 26th Annual International Conference, IEEE Engineering in Medicine & Biology Society (EMBS), San Francisco, USA.
Schor, C. M. & Bharadwaj, S. R., (2004). Pulse-step model of accommodation in the aging eye. ARVO, Ft. Lauderdale, USA.
Bharadwaj, S. R. (2003). What is so special about the contrast sensitivity function?. CME on Applications of Fourier Analysis to Human Visual System, Sankara Nethralaya, India.
Bharadwaj, S. R., & Schor, C. M. (2003). First & second order dynamics of accommodation and disaccommodation. Fall Vision Meeting, Tucson, USA.
Schor, C. M., & Bharadwaj, S. R. (2003). A dual-mode model describing accommodation dynamics. Society for Neuroscience, New Orleans, USA.
Mori, G., Walker, L., Bharadwaj, S. R., Schor, C. M., & Malik, J. D. (2003). Do object viewing strategies change when parts are ambiguous? ECVP, Paris, France.
Bharadwaj, S. R. & Schor, C. M. (2003). Peak velocity of accommodation is dependent on duration of acceleration. ARVO, Florida, USA.
Bharadwaj, S. R. (2003). Peak velocity of accommodation is acceleration duration dependent. L V Prasad Eye Institute, Hyderabad, India.
Bharadwaj, S. R. (2002). 3-dimensional rotational kinematics of eye movements. Sankara Nethralaya, Chennai, India.
Joseph, I. S., & Bharadwaj, S. R. (2001). Spatial frequency adaptation in human face perception. 5th Optometric Association of India Conference, Calcutta, India.

Anonymous reviewer responsibility

Experimental Eye Research
Graefes Archives for Clinical & Experimental Ophthalmology
Investigative Ophthalmology & Visual Science
Journal of Vision
Ophthalmic & Physiological Optics
Optometry & Vision Science
Vision Research

Professional affiliations

Teaching experience

2010 -: Course in-charge for Binocular vision and its anomalies. Bausch & Lomb school of Optometry, L V Prasad Eye Institute.
2004: Graduate student teaching consultant. Department of Optometry and Vision Science at UC Berkeley School of Optometry.
2002 - 2004: Oculomotor Functions and Neurology. Teaching assistant to Prof. Clifton Schor at UC Berkeley School of Optometry.
2002 - 2004: Binocular Vision and Space Perception. Teaching assistant to Prof. Martin Banks at UC Berkeley School of Optometry.
2003: Optometry research project. Reader assisting Prof. Theodore Cohn.

Software skills

Operating Systems: Windows 9x - Windows 7, Mac OS
Programming Languages: Microsoft Visual Basic; Psychophysics Toolbox - MATLAB interface
Statistical Softwares: MATLAB, IGOR pro, Microsoft Excel

Software development

Developed software for the diagnosis and training of the following sensory and oculo-motor functions
Aniseikonia
Graphical analysis of the zone of clear & single binocular vision
Horizontal and Vertical vergence
Horizontal fixation disparity
These softwares were written using the Psychophysics Toolbox application of MATLAB. They are being used in the Binocular & Visual Development Skills Clinic, School of Optometry, UC Berkeley.

Family

Well, that's when the four of us decided to venture into a studio to get ourselves photographed!! That's my amma and appa standing while allowing my brother and myself to sit comfortably during the photo shoot. If, in case you are wondering what my family is upto, here is some information for you...

My dad, V. S. Rajangam, works as a marketing consultant for building products. He loves travelling so much so that he dosen't mind getting lost in transit (Well, that is an inside joke, not many of you are going to understand it)!! One other thing he loves doing is getting both his sons out of the bed early in the morning. He comes up with such ingeneous ideas that any dad/mom viewing this page should make it a point to email him (gitarajangam [at] yahoo.co.in) to get advise!

My mom, Gita Rajangam, decided to quit her job as a bank officer to nurture her sons. She now repents doing that because inspite of her constant care, both her sons have turned into absolute morons!! She loves to do almost everything in this world; given a chance, she might even consider replacing me in graduate school.

Now, here comes the big guy, my younger brother, Prashant Bharadwaj!! A lazy-lubber, couch-potato, lotus-eater and what not; Prashant has the amazing ability of procastinate things to the last minute and still getting it done on time. Prashant is a Bio-Technologist by profession and he is currently pursuing a PhD in the molecular biology of Alzheimer's disease at CSIRO, Melbourne, Australia. Apparently, he had the so-called "engineering brains" right from childhood. I guess, my extended family inferred this when they saw him terrorizing people with a screw-driver and mallet when he was barely two years old!! I don't think he has a website of his own, but if he has one in the future, I should have the link for that somewhere here.

And finally, that's me, Shrikant Bharadwaj. I decided to pose a very professional look for the photograph, but it turned out as pathetic as ever!! Anyways, you have probably seen a lot of me by now. If you are still not fulfilled, go again to my main page and follow the routine!!!

There is one other important person who is not featured in this picture - my wife, Charanya Ramachandran. Charan is pursuing her PhD at the IU School of Optometry, Bloomington, working on the molecular biology of cell-cell interactions in corneal endothelium and trabecular meshwork (stuff, that is way too cool, but beyond my level of understanding!!). We met nine years back at the Elite School and we got married in February 2006. I am still waiting for a good picture of all five of us that could replace the existing one!

If you are curious to know, how both Prashant and myself ended up with a surname while my parents did not, here is the answer. My mom and dad decided to have kids when they were in Bombay (now called, Mumbai). It is customary to ask for ones surname first if you live anywhere in the north of India. Aad Nav Kai???, is how you would ask for a person's surname, if you knew to speak Marathi!!! My parents did not want their sons to be groping for an answer if such a question was posed. Hence, they decided to donne us with a surname, Bharadwaj after our gothram!!

You know what, there are other good things that my family is upto. If you want to know more, you can either choose to email them at gitarajangam [at] yahoo.co.in or myself at bharadwaj [at] gmail.com

Schor Lab home | UC Berkeley | School of Optometry