Compendium of Research

The faculty at Berkeley Optometry constitute a prestigious group of educators and researchers. This compendium of research provides a quick summary of their work and research interests.

Marty Banks, PhD

Professor of Optometry and Vision Science

Our research involves three topics: (1) the use of motion and stereoscopic information to determine the spatial layout of the visible environment and one's motion through that environment, (2) the combination of information from more than one sense modality (e.g., vision and touch), (3) the construction and evaluation of devices for creating useful virtual environments (e.g., vision, vestibular, and touch).

Banks Lab Website

Lu Chen, MD, PhD

Professor of Optometry and Vision Science

Unlike blood vessels which have been studied extensively in the past, lymphatic research represents an explosive field of new discovery largely owing to the recent identification of several lymphatic specific markers. The cornea provides an ideal tissue for vascular studies due to its accessible location, transparent nature, and vessel-free and vessel-inducible characters. Once induced, corneal lymphatic vessels enhance high volume delivery of antigens and immune cells, and accelerate inflammation and transplant rejection. Our primary long-term goal is to elucidate the basic molecular and cellular mechanisms underlying lymphatic vessel development and to discover novel therapeutic targets for lymphatic-related diseases both inside and outside of the eye.

Research on corneal lymphatic vessels has broader clinical implications beyond the treatment of ocular diseases alone, since the lymphatic network penetrates most tissues in the body, and its dysfunctions are involved in a diverse array of disorders which include but are not limited to cancer metastasis, diabetes, delayed wound healing, autoimmune diseases, and lymphedema.

Chen Lab Website

Susanna Chung, OD, PhD

Professor of Optometry and Vision Science

Research in our lab focuses on the understanding of how the visual system works in people with normal vision, as well as in people with uncorrectable subnormal vision (visual impairment). Uncorrectable sub-normal vision can occur as a result of an eye disease (e.g., age-related macular degeneration, the leading cause of visual impairment in the US for people over the age of 65), or even in the absence of an eye disease (amblyopia, or "lazy eye").

Chung Lab Website

Emily Cooper, PhD

Assistant Professor of Optometry and Vision Science

The long-term goal of our research is to understand how vision functions in the natural environment, and to apply these scientific insights to make perceptually meaningful improvements in human-display interaction. Working towards this goal, we employ techniques from psychophysics, computational modeling, eye-tracking, and display system engineering. Combining these techniques allows us to draw quantitative conclusions about natural visual function, and it maximizes our ability to apply this knowledge to impact new technological developments.

Cooper Lab Website

John Flanagan, PhD, DSc(hon), FCOptom, FAAO

Dean and Professor of Optometry and Vision Science

The Flanagan lab is interested in glial cell activation, in particular astrogliosis; cellular models of glaucoma, capable of manipulating biomechanical stretch and ischemia; animal models of chronic and acute ocular hypertension; biomarkers, proteomics and lipidomics; biomechanics of the lamina cribrosa of the optic nerve; ocular hemodynamics; clinical psychophysics and imaging (structure and function); aspects of spatial and temporal vision processing; and ocular chronobiology, particularly as it relates to glaucoma.

Flanagan Profile Page

John Flannery, PhD

Professor of Optometry and Vision Science

Retinal Degeneration and blindness result from the loss of rod and cone photoreceptors due to mutations in these cells or in their closely interacting and supportive retinal pigment epithelium (RPE), from environmental or poorly defined age-related factors, or the actions of other retinal neurons, glia or vascular elements. Relatively little is known about precisely why photoreceptors die in any of the many different retinal degenerations, and virtually no effective therapy exists for most of these diseases.

Flannery Lab Website

Suzie Fleiszig, OD, PhD, FAAO

Professor of Optometry and Vision Science

Research in my laboratory focuses on the pathogenesis of bacterial infections of the cornea. The principal aim of my research is to determine why patients who wear contact lenses are prone to infectious keratitis. These infections most often involve the bacterium Pseudomonas aeruginosa and can lead to severe vision loss. The results of initial studies indicated that ocular flora is altered in some contact lens wearers and that a large proportion of patients’ lens cases are contaminated with bacteria during normal use. However, neither of these phenomena entirely explain the pathogenesis of infection, since in general bacteria cannot infect a healthy cornea, even when introduced in large numbers. This implies that there must be some form of compromise, in addition to bacterial contamination of the eye before the infectious process can begin.

Fleiszig Lab Website

Xiaohua Gong, PhD

Professor of Optometry and Vision Science

Research in our lab has been directed toward the study of molecular and cellular mechanisms that control vertebrate organ-genesis and diseases, mainly, eye development and ocular diseases, by using multidisciplinary techniques from the fields of molecular and cellular biology, genetics, biochemistry, and electrophysiology etc. We are particularly interested in identification and characterization of novel genetic factors that play essential roles in the development of the eye as well as in pathological processes of diseases such as retinal degeneration, vascular disorders, and cataracts.

Gong Lab Website

Karsten Gronert, PhD

Professor of Optometry and Vision Science

These lipid circuits are essential components of a “resolution program” that helps remodel injured tissue, removes spent white blood cells and naturally terminates the inflammatory response. Intense research efforts in the last few years by a small group of research teams around the world has spurred enormous interest in these resident protective lipid circuits as a major target for the development of much needed novel drugs for the treatment of inflammatory diseases. Our research team is focused on elucidating the role of these endogenous protective circuits in inflammation and wound healing and to define their critical regulation by dietary omega-3 PUFA (fish oils). Karsten Gronert was a member of the research team that discovered that fish oils (omega-3 PUFA) are converted to specific protective lipid signals in the body. These findings have provided a molecular mechanism for the remarkable beneficial actions of dietary omega-3 PUFA, which has eluded scientist for decades.

Gronert Profile Page

Stanley Klein, PhD

Professor of Optometry and Vision Science

Single Cone Psychophysics. We are using Austin Roorda’s adaptive optics scanning laser ophthalmoscope (AOSLO) for human psychophysics. The AOSLO has the capability of stimulating individual cones repeatedly, with the ability to go to the same cones over years. AOSLO’s unique capabilities enable us to learn about fine-grained spatio-temporal-chromatic nonlinear visual processing that was previously not available for investigation. Modeling of Spatial Vision. The visual system is assumed to consist of an enormous number of spatial filters with different positions, sizes, orientations and bandwidths. These filters are arranged in sequential stages with nonlinear interactions between and within the stages. Nonlinear Systems Analysis with Application to Localizing VEP Sources. The use of fMRI and MRI scans for imaging brain activity has created much excitement among brain researchers. We have developed a new approach that combines nonlinear analysis, MRI, fMRI and the visual evoked potential (VEP) should reveals the underlying neural generators of visual cortex with a temporal resolution 100-1000 times better than is possible with fMRI.

Klein Lab Website

Dennis Levi, OD, PhD

Professor of Optometry and Vision Science

Specifically, we use psychophysics, computational modeling and brain imaging (fMRI) to study the neural mechanisms of normal pattern vision in humans, and to learn how they are degraded by abnormal visual experience (amblyopia). While amblyopia is known to influence the properties of neurons in cortical area V1 recent work in our laboratory suggests that amblyopia may also result in damage to higher cortical areas.

Levi Lab Website

Meng Lin, OD, PhD

Professor of Clinical Optometry and Vision Science

We also provide training for young professionals who are interested in, or want to pursue careers in, clinical research. In addition to directing the Clinical Researdh Center (CRC), Dr. Lin is also Chief of the Ocular Surface Imaging Clinic, and Co-Chief of the Dry Eye Clinic at Berkeley Optometry. Other duties include Co-Director of theTranslational Research CORE Facility.

Dr. Lin’s current research interests include, but not limited to the following areas: (1) effect of contact lenses and lens care solutions on ocular surface integrity (specifically on rheology of tear lipid layer and corneal epithelial barrier function); (2) effects of lens care solutions on contact lens surface wettability and their long-term clinical implications; (3) inherent differences in ocular surface integrity among different ethnic groups and how these differences contribute to success or failure in contact-lens wear and other ophthalmic treatment modalities; (4) mechanisms responsible for tear film stability; (5) understanding post-lens tear flow resistance under contact lenses including scleral lenses ; (6) advancing diagnostic clinical tools/tests for evaporative dry eye; and (7) applications of machine learning on ocular surface image process.

Meng Lin Profile Page

Maria Liu, OD, PhD

Associate Professor of Clinical Optometry and Vision Science

The emphasis of my research has been on the investigation of optical influences on emmetropization and the development of myopia. Using chicken as a model, I have identified a number of optical designs that significantly inhibit myopia progression, thus have potential translational value in controlling human myopia. Additionally, I have been designing and fitting contact lenses to young guinea pig cornea to evaluate the safety, feasibility and effectiveness of contact lenses as a method of inducing defocus for myopia research in mammalian models.

Maria Liu Profile Page

Nancy McNamara, OD, PhD

Associate Professor of Clinical Optometry and Vision Science

Mucosal epithelial cells interface with the environment at all body surfaces, including the eye. Thus, the mucosa is often the first line of defense against environmental injury. Mucosal cells use a general defense strategy and are believed to play a critical role in regulating the more powerful adaptive immune response. Unfortunately, sometimes the immune system goes into overdrive and creates a pathological state. Examples of this include ocular allergy, dry eye disease, bacterial infection and even cancer. In each of these disease entities there is an immunological component that either initiates or enhances the disease state. Dr. McNamara’s work focuses on dissecting the molecular events that underlie early immune responses. Her research program involves clinical studies of the human ocular surface, as well as both in vivo and in vitro studies of the immune pathways that promote inflammation in the pathological state. This work will lead to a better understanding of the molecular patterns that contribute to pathology and suggest new strategies for modulating the response in favor of the host.

Nancy McNamara Profile Page

Bruno A. Olshausen, PhD

Professor of Vision Science, Optometry and Neuroscience

One major line of work is to develop probabilistic models of natural images, and to construct neural circuits capable of representing images in terms of these models. For example, we have developed a model of natural images based on the principle of sparse coding — in which the retinal image is explained in terms of a small number of events at any given point in time — and we have shown that the receptive field properties that emerge in such a system match those found in the primary visual cortex (V1) of mammals. The suggestion then is that V1 may be operating, at least in part, according to a similar principle. We are currently working on extending this model to learn invariances from natural image sequences, in addition to building models composed of multiple layers to capture the hierarchical structure of visual cortex.

Olshausen Lab Website

Deborah Orel-Bixler, OD, PhD, FAAO

Professor of Clinical Optometry and Vision Science

The primary goal of the VIP Study is to determine whether there are tests or combinations of tests that can be used effectively to determine which preschoolers would benefit from a comprehensive eye examination to detect amblyopia, strabismus, significant refractive errors, and associated risk factors.

Orel-Bixler Lab Website

Jorge Otero-Millan, PhD

Assistant Professor of Optometry and Vision Science

Vision while moving
If we could record a video of what our eyes see while we move around in the world, we would see an image that continuously moves, rotate, and jumps from place to place. Despite all that motion our perception of the world around us is stable. In the lab we are interested in understanding how our brain achieves this by studying visual perception in the presence of eye and head rotations around their three axes: yaw, pitch, and roll.

Measuring eye movements
Precisely and accurately measuring eye movements is critical for many fields of research, for clinical diagnosis, and more recently also for consumer applications. We are interested in developing new methods to measure and analyze all aspects of eye movements, for example, torsional eye position. We also want to understand the biases, artifacts, and limitations of current devices and methods to record eye position.

Eye movements for diagnosis
Disorders affecting vision, cognition, motor control, or our balance sensation will cause some abnormality in the eye movements of the patient. Eye movement recording capabilities are becoming ubiquitous on smartphones or headsets for virtual or augmented reality. This presents a huge opportunity to help diagnose or triage patients wherever they are. We want to combine our knowledge of ocular motor control and eye movement recording methods to best define what tests and features can help us diagnose the different disorders.

Otero-Millan Lab Website

Teresa Puthussery, OD, PhD

Assistant Professor of Optometry and Vision Science

Ongoing projects in the lab are addressing the following questions:

• How do retinal neurons extract specific features such as motion and spatial detail from the visual environment?
• How do different types of neurotransmitter receptors and ion channels shape the response properties of retinal neurons?
• How do mutations in the molecular machinery of cone-photoreceptors lead to retinal degeneration?
• How does the structure and function of the inner retinal circuitry change in response to photoreceptor degeneration?

Puthussery Lab Website

Austin Roorda, PhD

Professor of Optometry and Vision Science

The human eye has a complex and exquisitely designed optical system, yet when compared with modern optical systems, its image quality is surprisingly poor. Our lab investigates these earliest stages of vision, from the formation of the retinal image to its sampling by the photoreceptor mosaic.

In our research we develop novel instruments to measure and overcome the optical limits of the eye. For example, we employ adaptive optics — a technology originally developed for astronomical imaging from ground-based telescopes — to correct the eye’s aberrations and to image and/or present stimuli to the retina with unprecedented resolution. Overcoming optical limitations with adaptive optics has allowed us to make new discoveries in vision science, from mapping the trichromatic cone mosaic for the first time ever to learning how human visual acuity responds to an aberration correction.

Roorda Lab Website

Michael Silver, PhD

Professor of Vision Science, Optometry and Neuroscience

We address these questions with a combination of behavioral, neuroimaging, electrophysiological, modeling, and pharmacological techniques to study both healthy human participants as well as patients who suffer from diseases that affect perceptual processing. Specifically, we are investigating the neurophysiological and neurochemical substrates of visual attention and perceptual learning, effects of acetylcholine on perception, memory, and neural representations, visual processing in schizophrenia, binocular rivalry, functional subdivisions of the lateral geniculate nucleus, representation of visual space in the brain, and auditory perception.

Silver Lab Website

W. Rowland Taylor, PhD

Professor of Optometry and Vision Science; Researcher

The goal of my research is to understand how neural circuits within the mammalian retina encode and transmit information about the visual environment. The experimental work emphasizes quantitative measurements of neural responses to natural stimuli in the intact retina. We also perform immunohistochemical studies to localize transmitter receptors and channels within specific neural circuits. Additionally, we construct computer models of neurons and circuits, based on realistic morphologies and neural connectivity, and run simulations of circuit function to further test our understanding, and to generate experimentally testable predictions.

Taylor Lab Website

Will Tuten, OD, PhD

Assistant Professor of Optometry and Vision Science

This sensory capacity is remarkable considering our visual percepts are constructed from just three types of photoreceptor signals—those arising from L, M, and S cones. To obtain an accurate estimate of the spatio-chromatic structure of the world, the circuitry of the retina and brain must process the signals originating in cones across space and time. We use single-cone psychophysics to study these processes near the human fovea, where our visual sense is finest.

Degenerative diseases of the outer retina result in the death of rod and cone photoreceptors. These structural losses necessarily occur at the cellular scale, and have traditionally been studied by histology—either in animal models or in post-mortem human tissue. By contrast, much of our knowledge about the functional consequences of degenerative retinal disease has been acquired using relatively coarse tools for probing vision: visual acuity measurements and conventional automated perimetry. To examine structure-function relationships at the cellular scale in living eyes, we use multi-modal adaptive optics high-resolution retinal imaging in conjunction with precise cone-targeted stimulation. The tools we develop to achieve this have the potential to enhance our understanding of how retinal diseases develop, progress, and respond to therapeutic intervention.

Will Tuten Profile Page

Christine Wildsoet, OD, PhD

Professor of Optometry and Vision Science

My research interests are mainly centered around refractive development and myopia (short-sightedness), although my interests extend beyond this to include intraocular pressure regulation and glaucoma therapy, and ocular public health issues. I have on-going collaborations, both within and outside the USA, both in myopia research and outside it. The etiology of human myopia is poorly understood; while genetic factors once were considered the main determinant, the current epidemic of myopia in some populations (near 90% in some Asian university student populations!), suggests that the picture is far more complex. Visual experience appears to be an important factor, with near work being apparently provocative although not everyone appears equally susceptible. There are currently as many unanswered questions and answered ones in terms of what aspects of the visual experience are important, the nature of myopia growth signals, and how eyes enlarge.

Wildsoet Lab Website