Join the OSA Vision Technical Group for a virtual seminar featuring talks from Larry Thibos and Michael Bach. The seminar will review fundamental vision science concepts, including visual acuity as a function of retinal illumination; understanding the limitations of visual perception through optical illusions and visual phenomena; and future directions in the field.
Imaging in our brain – Optical illusions neither “trick the eye” nor “fool the brain” by Michael Bach: Our vision appears to us totally effortless, yet perception of images, objects, color and motion involves complicated, ill-understood processes in our brain. We assume what we see is pretty much what our eyes have seen and have transmitted to the brain. Rather, our visual system continuously “invents” an inner world as a basis for understanding and planning, based on incomplete information. This rests on experience, both evolutionary and individually; more formally this is the Bayesian interpretation of perception. When experience does not fit the current situation, ensuing missteps of our perceptual apparatus are called optical illusions and can reveal some of these endogenous mechanisms. Thus, optical illusions neither trick the eye nor fool the brain. The talk will present demonstrations of these processes, organized along the visual dimension luminance, color, motion, space, and gestalt.
Starbursts: their nature, origin, and visual importance by Larry Thibos: Starbursts, an entoptic phenomenon that has been observed and recorded throughout history, are dim lines that appear to radiate from stars and planets when viewed against the night sky. Psychophysical experiments, combined with optical analysis, indicate that starbursts are the subjective manifestation of light caustics formed on the retina by the eye's optical aberrations. Starbursts have special relevance to visual astronomy because they reduce the visibility of celestial objects and hamper the spatial resolution of neighboring objects.