Improving Adult Vision Through Pathway-Specific Training in Augmented Reality.

Neurodevelopmental and neurodegenerative disorders are often associated with selective deficits in the parallel pathways of the human visual system. Effective intervention of the visual deficits is crucial for improving treatment outcomes and prognosis. In this study, a novel altered reality (AR) method is developed to improve pathway-specific functions in human adults with normal vision and amblyopia, a common developmental vision disorder. To selectively enhance the parvocellular pathway, which is notably impaired in amblyopia, the low spatial frequency (SF) components of visual input are phase-scrambled into fast-flickering noise, while the high SF details remained intact. In normal participants, short-term adaptation to this altered naturalistic environment led to selective enhancement of high SF sensitivity and visual acuity. Long-term adaptation to a dichoptically modified environment produced long-lasting improvement of high SF sensitivity and dominance of the weaker eye, with enhanced neural responses to high SF naturalistic stimuli. After one week of training with wearable AR glasses at home, amblyopic adults showed high treatment compliance and significant gains in visual acuity and dominance of the amblyopic eye, as well as in stereopsis. This AR-based, pathway-specific training method can be effective for improving visual functions in both healthy adults and patients with visual disorders.