Visual Neuroscience
Area of Research
Clinical Translational Research Biomedical Optics Visual NeuroscienceInterests
Noninvasive functional and structural evaluation of the visual pathways under normal and pathological conditions
Han Cheng,O.D., Ph.D.
Clinical ProfessorDr. Cheng earned both her PhD and OD degrees from the University of Houston, College of Optometry. After graduation, she became an associate in a private practice at Sugarland, Texas. She joined the MacGregor Medical Association in 1999 and practiced optometry there until she became a faculty member at the UH College of Optometry in 2002.
Area of Research
Visual NeuroscienceInterests
spatial vision, color vision, reading, and statistical and psychophysical methods
Daniel R. Coates,Ph.D.
Assistant ProfessorDr. Coates received his PhD in Vision Science from the University of California, Berkeley in 2015, where he studied letter recognition, peripheral visual perception, and crowding, using psychophysics and computational modeling. After postdoctoral appointments in Belgium and Switzerland studying the relationships between crowding, attention, and appearance, he joined the faculty of UHCO in 2017.
His research and teaching interests include spatial vision, color vision, reading, and statistical and psychophysical methods. He is passionate about the use of open source tools for experimentation, analysis, and learning.
Area of Research
Visual NeuroscienceInterests
neural mechanisms that are affected in the different forms of strabismus; information processing in neural oculomotor circuits
Vallabh Das,Ph.D.
ProfessorDepartment Chair, Vision Science
I received my undergraduate degree from the Birla Institute of Technology and Science, Pilani, India in 1992 majoring in Electronics Engineering. I then moved to the United States for graduate studies and completed a M.S and Ph.D. degree in 1998 in Biomedical Engineering from Case Western Reserve University, Cleveland, Ohio. My work, carried out under the mentorship of Dr. John Leigh, primarily examined the interactions between visual-oculomotor and vestibular systems. I did post-doctoral work at the Yerkes National Primate Research Center, Emory University with Dr. Michael Mustari from 1999 to 2002. During this time I learnt the technique of single cell extracellular recording in the awake-behaving monkey and also became interested in examining visual-oculomotor mechanisms in the strabismic primate. I was appointed to the faculty at Emory University in 2002 and received an independent investigator award from the National Institutes of Health in 2004 to study neural circuits mediating binocular coordination of eye movements in the strabismic monkey. I have since maintained continued NIH funding. I joined the faculty of the College of Optometry, University of Houston in 2009. The goal of research in my laboratory is to continue to uncover the disruption of neural processing in various brain areas in the strabismic monkeys. A better understanding of neural mechanisms that are affected in the different forms of strabismus will help develop rationally based therapy.
Area of Research
Biomedical Optics Ocular Biology Visual NeuroscienceInterests
Neural circuit and synaptic remodeling in retinal development and degeneration.
Luca Della Santina,Ph.D., Pharm.D.
Assistant ProfessorDr. Della Santina received his M.S in medicinal chemistry, Pharm.D. in pharmacy and Ph.D. in Neuroscience from the University of Pisa. He moved to the United States as a postdoctoral fellow at the University of Washington, Seattle under the supervision of Dr. Rachel Wong. Following his postdoctoral training, he was a research faculty at the University of Pisa, Italy and at the University of California, San Francisco before joining the faculty at the College of Optometry, University of Houston in 2021. His research focuses on investigating the functional, circuit and synaptic rearrangements of the retina following to neurodegenerative diseases, to identify novel cellular targets for early detection and treatment. His research laboratory develops novel computational tools for large-scale recording of neurons and identification of neural circuits, as well as computer vision approaches based on deep learning for the automatic detection of ocular diseases in clinical and smartphone photographs.
Area of Research
Ocular Biology Visual NeuroscienceInterests
Retinal physiology, non invasive assessment of retina and anterior visual path in normal and disease
Laura J. Frishman,Ph.D., FAAO, FARVO
ProfessorAssociate Dean for Graduate Studies and Research
Dr. Frishman has been on the faculty of the College of Optometry since 1990 and currently serves as the Associate Dean for Graduate Studies and Research. She received her undergraduate degree from Vassar College and her MS and PhD in physiological psychology/neuroscience from the University of Pittsburgh. She did postdoctoral training in visual neuroscience at Northwestern University and the University of California San Francisco where she also was a research faculty member. Dr. Frishman has taught in both the professional and graduate programs in the College of Optometry. Her research has focused on refining noninvasive electrophysiological approaches for evaluating retinal and anterior visual pathway function in normal subjects and subjects with inherited or acquired diseases that affect visual function.
Dr. Frishman currently serves as an Associate Editor for Investigative Ophthalmology and Visual Science, she is on the editorial board of Translational Vision Science and Technology and she is an academic editor for PloS One. Previously she served as Editor-in-chief of the Journals, Visual Neurocience, and Documenta Ophthalmological. Dr. Frishman has served on federal grant review panels, the NIH/NEI National Advisory Eye Council, and she is a fellow of the Association for Research in Vision and Ophthalmology (FARVO), American Academy of Optometry (FAAO) and a board member of the International Society for the Clinical Electrophysiology of Vision (ISCEV).?
Area of Research
Visual NeuroscienceInterests
Gap junctions in the retina, rod-cone coupling
Nange Jin,M.D., Ph.D.
Research Assistant ProfessorDr. Nange Jin received his M.D. in Clinical Medicine from Yanbian University College of Medicine in China. He earned his Ph.D. in Medical Science with a major in physiology & biophysics at the Seoul National University in South Korea. Afterwards, he received post-doctoral training in the Department of Physiology & Cell Biology at the University of Nevada School of Medicine, Reno. His research now includes the effects of rod-cone coupling plasticity on downstream retinal circuits that control both the image-forming and the non-image-forming visual pathways. Dr. Jin conducted some of this research within Christophe Ribelayga’s laboratory at the University of Texas Health Science Center. Dr. Jin will be joining the department of Vision Sciences as a Research Assistant Professor.
Area of Research
Clinical Translational Research Biomedical Optics Visual NeuroscienceInterests
Development of vision, Anomalies of Binocular Vision, Refractive Error, and Vision Screening Clinical research
Ruth Manny,O.D., Ph.D., FAAO
Charles R. Stewart ProfessorDr. Manny received her OD, MS and PhD from the University of Houston, College of Optometry. While earning her graduate degrees she worked part-time in a private practice in Clear Lake, TX. Her clinical expertise is pediatric eye care with an emphasis on infants and preschoolers and those with differing abilities. She has served as the principal investigator for a variety of multi-center studies funded by the National Eye Institute and industry. These studies included clinical trials investigating the development, progression and treatment strategies for myopia (COMET, COMET2, ACHIEVE, CLIP), large collaborative observational studies of myopia (CLEERE, COSMICC), and collaborations with the Pediatric Eye Disease Investigator Group (PEDIG) on treatment strategies for amblyopia and strabismus. She has served on the PEDIG executive committee and as Vice Chair. Additional interests include improving methods to identify young children with or at risk for vision problems. She has served as Chair of the Clinical Science department, and Service Director for the Pediatric Specialty Clinic. Dr. Manny has been on the editorial board of Optometry and Vision Science and served as a topical editor for the journal. She is a fellow of the American Academy of Optometry, and the Association for Research in Vision in Ophthalmology and is active in shared governance through the faculty senate serving on the executive committee and many senate committees.
Cherlyn J. Ng,Ph.D.
Sr Research ScientistCherlyn Ng was born and raised in Singapore, where she went on to earn her BSc in neuroscience and PhD in x-ray crystallography from the National University of Singapore. Drawing upon her earlier experiences with audio/visual production, she received postdoctoral training in computational modeling, psychophysics and developed a deep interest in visual perception. Her current interests focuses on how the brain processes and represents sensory information, with particular emphasis on binocular vision. However, traditional psychophysics does not distinguish between percepts that arise from neural mechanisms and visual limitations that are caused by the imperfect optics of the eyes. She addresses this conundrum by coupling psychophysics with adaptive optics technology. This method minimizes optical limitations by correcting for the optical aberrations in the eyes so that percepts brought about by the neural mechanisms can be measured in isolation. These measurements serve the eventual purpose of building a unified model that explains how the brain chooses between selecting and balancing information from the two eyes.
Area of Research
Visual NeuroscienceInterests
Roles of recurrent connections between cortical areas in visual computation and perception.
Lauri Nurminen,Ph.D.
Assistant ProfessorI study cortical mechanisms of visual perception. Currently, I am interested in the roles of interactions between areas of the visual cortex in visual perception.
My work contributes to our understanding of how the brain generates subjective experiences, and how disrupted neural circuit function leads to altered visual perception in neuropsychiatric disorders that affect visual perception (e.g. autism, schizophrenia, Parkinson’s disease).
My laboratory uses a combination of methods including high-density electrophysiology, optogenetics, and behavioral techniques.
Before starting a laboratory at the UH, I did a PhD at the University of Helsinki, and postdoctoral training at the University of Utah and the Salk Institute.
My work is funded by the NIH, University of Houston, and Kavli Foundation.
Area of Research
Ocular Biology Visual NeuroscienceInterests
Electrical synapses in retinal neurons, gap junctions
John O'Brien,Ph.D.
ProfessorDr. John O’Brien joined UHCO as a Professor in Vision Science in 2021. Dr. O’Brien earned his B.A. in Biochemistry at Bowdoin College in Brunswick, Maine and his Ph.D. in Biochemistry at the University of California, San Diego. Dr. O’Brien entered the field of vision research in a post-doc with mentors Harris Ripps and Muayyad Al-Ubaidi at the University of Illinois at Chicago. There he cloned connexins that form electrical synapses in retinal neurons, setting the stage for a large fraction of the research he has performed since then. In 1998, Dr. O’Brien joined the Ophthalmology faculty at the University of Texas Health Science Center at Houston, in which his lab conducted research on retinal electrical synapses. Dr. O’Brien has published extensively on this topic and has been funded by the National Eye Institute (NEI) since 2000. Dr. O’Brien has recently begun to study regeneration of rod photoreceptors in a transgenic zebrafish model of Retinitis Pigmentosa developed in his lab. His group has applied single-cell transcriptomics to map out transcriptional pathways involved in the proliferation and differentiation of progenitor cells to form new rods and to study the role of microglia in retinal regeneration. His lab is applying a variety of molecular and genetic techniques to investigate these pathways.
Area of Research
Clinical Translational Research Biomedical Optics Visual NeuroscienceInterests
Myopia, circadian rythms and eye growth nvironmental and behavioral influences on circadian rhythm and eye growth.
Lisa Ostrin,O.D., Ph.D., FAAO
Associate ProfessorDr. Ostrin is an Associate Professor at the University of Houston College of Optometry. She received a Bachelor of Arts degree in Fine Arts at the University of Texas at Austin. She then completed the combined OD/PhD program at the University of Houston College of Optometry. Following graduate work focused in accommodative physiology, she went to John Hopkins University for post-doctoral research in low vision and retinal prosthetics. From there, she worked as a Clinician Researcher at the University of California Berkeley School of Optometry, with a focus on myopia and associations with glaucoma. She returned to the University of Houston as faculty to continue her work in myopia and circadian rhythms. In addition to research, Dr. Ostrin teaches gross and ocular anatomy, and has authored a book, Anatomy of the Human Eye: a Coloring Atlas. Dr. Ostrin is a fellow of the American Academy of Optometry, Gold Fellow of ARVO, and a recipient of the American Optometric Foundation Ezell Fellowship.
Area of Research
Clinical Translational Research Biomedical Optics Ocular Biology Visual NeuroscienceInterests
Optical coherence tomography, structure-function relationships in glaucoma, algorithm development for early detection of optic nerve pathology
Nimesh Patel,O.D., Ph.D., FAAO
Associate ProfessorDr. Patel graduated from the Southern College of Optometry, Memphis Tennessee in 2002, after which he completed a residency in Family Practice at Northeastern State University Oklahoma College of Optometry. He completed his graduate work at the University of Houston, earning a PhD in 2012, and has been on the faculty since. His current research is on improving structural measures of the optic nerve head, retinal nerve fiber layer and macula regions using optical coherence tomography, and investigating the relationship between these structural measures and visual function. He also teaches students in the classroom, laboratory and clinical settings.
Area of Research
Ocular Biology Visual NeuroscienceInterests
Circadian clocks and retinal development, plasticity in network of coupled photoreceptors.
Christophe Ribelayga,M.S., Ph.D.
ProfessorFoundation for Education & Research in Vision (FERV) Professor
Dr. Ribelayga received his M.S. (1995) and Ph.D. (2000), both in Neuroscience, from the University Louis Pasteur in Strasbourg, France. He then did post-doctoral work at the University of Alabama at Birmingham (UAB) (1999-2005). During this time, he used techniques of single cell recording in the retina to examine how circadian clocks within the retina control the light responses of retinal cells. He joined The Ohio State University (OSU) School of Medicine in Columbus, OH as a Research Assistant Professor (2005-2009) and subsequently moved to The University of Texas at Houston (UTHealth) McGovern Medical School as an Assistant Professor of Ophthalmology. Dr. Ribelayga was promoted to Associate Professor with tenure in 2016 and awarded the Bernice Weingarten Endowed Chair in Ophthalmology in 2019. Dr. Ribelayga joined the University of Houston College of Optometry (UHCO) in 2021, where he is Professor of Physiological Optics and Vision Science. His work has long focused on two areas of research: 1) the role of circadian clocks in the development, maintenance, and function of retinal cells, and 2) the functional architecture of the network of coupled photoreceptors, its plasticity, and the impact of this plasticity on retinal circuit processing and visual perception. Although Dr. Ribelayga’s research accomplishments are primarily in basic science, his work may have important clinical relevance and has been continuously supported by NIH.
Area of Research
Biomedical Optics Ocular Biology Visual NeuroscienceInterests
Human subjects, imaging, glaucoma, ocular disease, myopia
Diane N. Sayah,O.D., Ph.D.
Assistant ProfessorDr. Diane N. Sayah is an optometrist with special interests in ocular biomechanics and hemodynamics. She obtained her Doctor of Optometry degree from the University of Montreal. She then completed her PhD in glaucoma and biomechanics research at the Maisonneuve-Rosemont Hospital (University of Montreal) and worked as a postdoctoral fellow at the Harvard Retinal Imaging Lab (Massachusetts Eye and Ear).
Dr. Sayah served as lecturer and clinical instructor at the University of Montreal School of Optometry for over seven years before joining the University of Houston College of Optometry as an Assistant Professor (tenure-track).
As a clinician-scientist, Dr. Sayah's interests are directed towards neurodegenerative diseases of the eye, particularly glaucoma, as well as myopia. Benefiting from cutting-edge technology and innovative methods for probing biomechanical and choroidal involvement in eye diseases, her objective is to lead translational research which will directly improve clinical care.
Area of Research
Visual NeuroscienceInterests
Vergence eye movements and binocular coordination, stereoscopic depth perception, modeling of binocular image matching processes.
Scott B. Stevenson,Ph.D.
Associate ProfessorScott Stevenson received his PhD in Experimental Psychology from Brown University in 1987 for studies of visual suppression during eye blinks. He was an NRSA post-doc at UC Berkeley School of Optometry for three years, and then joined the research faculty there. Dr. Stevenson joined the faculty at UH in 1995.
Dr. Stevenson’s research concentrates on the visual control of eye movements, with emphasis on visually driven eye movement reflexes, such as for the control of eye alignment. Dr Stevenson is also active in the development of eye trackers based on high magnification retinal imaging in a broad collaboration involving researchers at a number of other institutions.
Dr. Stevenson teaches in courses on Vision Science, Perception, Optometry, Eye Movements, and Matlab for Vision Science.
Area of Research
Clinical Translational Research Biomedical Optics Visual NeuroscienceInterests
Optical quality of the eye and to improve visual performance by correcting the optical defects in the eye
Geunyoung Yoon,Ph.D
ProfessorIrvin M. Borish Professor
Dr. Geunyoung Yoon is currently appointed as the Irvin M. Borish Chair Professor at the University of Houston College of Optometry. He previously served as a faculty at the University of Rochester. His laboratory’s overarching research goal is to enhance our understanding of optical and neural mechanisms underlying vision and eye problems by conducting human-based translational research. To achieve this goal, his laboratory has been developing various state-of-the-art technology including advanced ocular aberrometers, wavefront-guided vision correction methods, binocular adaptive optics visual simulator, and in-vivo cornea/anterior segment imaging modalities. These capabilities have been used for studying mechanistic interactions between the optics of the eye and the neural system, vision improvement for patients with corneal pathologies, diagnosis and treatment of corneal diseases, presbyopia correction, and myopia development/control. Dr. Yoon’s laboratory is funded by NIH, other non-profit funding agencies, and the industry. He is a recipient of the Dolly Green Special Scholars Award, Research to Prevent Blindness, and David E. Bryant Trust Research Award. He is a panel member for the FDA’s Center for Devices and Radiological Health and serves as a member of the Editorial Boards of Frontiers in Ophthalmology, Annals of Optometry and Contact Lenses, and Journal of the Korean Ophthalmological Society.
Area of Research
Visual NeuroscienceZhijing Zhang,Ph.D.
Research Assistant ProfessorDr. Zhijing Zhang received his B.S. in Clinical Medicine from Tianjin Medical University, China, and a master’s degree in neuroscience from Peking Union Medical College. Dr. Zhang also holds a Ph.D. in Pharmacology from the University of Illinois at Chicago. He had post-doctoral training at the University of Texas MD Anderson Cancer Center where he focused on epigenetics and the development of the nervous system. Dr. Zhang worked as a research associate in Dr. Christophe Ribelayga’s lab at the University of Texas Health Science Center to study retinal functions.
Dr. Zhang joined the Department of Vision Sciences as a Research Assistant Professor. Dr. Zhang’s research interests focus on how circadian mechanisms and gap junctions affect retinal functions.