Project Prakash: Development of Object Perception After Late Sight Onset

Project Summary The World Health Organization estimates that globally nearly 13 million children are visually impaired, with over a million of them being blind. Over 80% of these children reside in third-world countries, with bleak prospects for medical care, even though in many cases, the conditions are treatable or preventable. The lives such children lead are difficult and deprived ones. Project Prakash (Sanskrit for `light') was born out of the realization that the humanitarian mission of bringing sight to blind children offers a valuable opportunity to address important scientific questions related to visual learning and brain plasticity. With support from NIH and philanthropic foundations, Project Prakash is operationalized as a three-part effort, comprising rural outreach, medical treatment and scientific research. The highly regarded Dr. Shroff's Charity Eye Hospital in Delhi serves as our medical partner. Pursuing its dual mission of service and science, the initiative has provided ophthalmic screening to over 62,000 children, sight restoring surgeries to over 520 blind children, and non- surgical care to over 2000 others. Several of the children treated for long-standing congenital blindness have gone on to participate in scientific studies designed to probe the development of visual proficiencies and cortical changes after sight onset. Following their visual progress has demonstrated both the possibility of, as well as constraints on, functional gains after several years of severely compromised pattern vision. Even as Prakash children are found to exhibit persistent impairments in basic aspects of visual function, such as acuity and contrast sensitivity, they are able to acquire complex object perception skills in the months following surgery. Building on these results, our goal now is to elucidate the mechanisms that underlie the observed limitations and proficiencies in post-surgical development. Using psychophysical, electrophysiological, and neuroimaging techniques, we will attempt to determine, on the one hand, the neural bottlenecks that limit recovery and, on the other, the mechanisms, both neural and functional, that act as enablers of functional gains in object perception.