Long-Term Adaptation to Ocular Optics and Its Impact on Contrast Perception
Hosted By: Clinical Vision Sciences Technical Group
14 April 2023 14:00 - 15:00
Eastern Time (US & Canada) (UTC -05:00)The imperfect optics of the eye cause a significant reduction in the contrast of the retinal image. This contrast attenuation is more pronounced as spatial frequencies (SFs) increase and it limits our ability to perceive contrast near the threshold. Interestingly, when the contrast is well above the threshold, the perceived contrast is constant across a wide range of spatial frequencies. This could be explained by a phenomenon known as contrast constancy in which adaptation to blurred images alters neural processing to improve visual representations of the world.
In this context, a series of studies were conducted with an aim to elucidate how long-term visual experience with the habitual optical blur influences neural processing. In this webinar hosted by the Clinical Vision Sciences Technical Group, Dr. Geunyoung Yoon will discuss how he used an adaptive optics visual simulator to accurately correct or manipulate the eye’s aberrations and to assess visual processing psychophysically in highly aberrated eyes. Dr. Yoon found that (1) when the habitual aberrations were fully corrected, observers showed impaired sensitivity for higher SFs and better-than-typical sensitivity for lower SFs, and (2) they exhibited contrast constancy with their habitual optics while under-constancy (as opposed to expected over-constancy) was measured under full-correction of the aberrations. These findings suggest that adult neural processing adapts to better match the changes in visual inputs caused by the eye’s optics altered over time.
Subject Matter Level: Intermediate - Assumes basic knowledge of the topic
What You Will Learn:
• Ocular aberrations
• Contrast perception
• Contrast constancy
Who Should Attend:
• Researchers, clinicians and students with an interest in ocular aberrations, adaptive optics and visual perception.
About the Presenter: Geunyoung Yoon from the University of Houston College of Optometry
Dr. Geunyoung Yoon is the Irvin M. Borish Chair Professor at the University of Houston College of Optometry. His laboratory’s overarching research goal is to enhance our understanding of mechanisms underlying vision and eye problems by conducting interdisciplinary translational research involving various state-of-the-art technology including advanced ocular wavefront sensors, wavefront-guided contact lenses, binocular adaptive optics visual simulator, and in-vivo cornea/anterior segment imaging modalities. His current studies aim to study 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 industry. He is a recipient of the Dolly Green Special Scholars Award, Research to Prevent Blindness & David E. Bryant Trust Research Award.
