Enhancing visual performance in individuals with cortical visual impairment (homonymous hemianopsia): Tapping into blindsight

Homonymous hemianopsia is a type of cortical blindness in which vision is lost completely or partially in the left half or the right half of the field of vision. It is prevalent in approximately 12% of traumatic brain injury and 35% of strokes. Patients often experience difficulty with activities such as ambulating, eating, reading, and driving. Due to the high prevalence of homonymous hemianopsia and its associated difficulties, it is imperative to find methods for visual rehabilitation in this condition. Traditional methods such as prism glasses can cause visual confusion and result in patient noncompliance. There is a large unmet medical need for improving this condition. In this article, we propose that modifying visual stimuli to activate non-cortical areas of visual processing, such as lateral geniculate nucleus and superior colliculus, may result in increased visual awareness. Presenting high contrast and low spatial frequency visual stimuli can increase visual detection in patients with cortical blindness, a phenomenon known as blindsight. Augmented virtual reality goggles have the potential to alter real-time visual input to high contrast and low spatial frequency images, possibly improving visual detection in the blind hemifield and providing an alternative therapy for homonymous hemianopsia.