Project Summary/Abstract: The postnatal development of both the optical and neural visual systems is dependent on visual experience. Abnormal visual experience in infancy and childhood can lead to strabismus and amblyopia. The goal of the proposed research is to understand how the visual system controls its own visual experience by driving accommodation and vergence motor responses, in the context of these clinical conditions. There are three interrelated projects: i) To understand how information passing through the sensory visual system interacts with motor performance to permit typical development in most infants and young children. Newborns see poorly and yet are able to develop aligned binocular vision over the first weeks after birth. This aim will test hypotheses about how they are able to do this. ii) To understand the interaction between the sensory and motor visual systems in children with hyperopia, to determine why some children with hyperopia develop strabismus and amblyopia while others function apparently normally. This aim will test hypotheses and build models related to cue use by the motor system and the information available to the sensory visual system. iii) To understand how anisometropia and misalignment of the eyes disrupt neural function to precipitate the lasting neural adaptations underlying strabismus and amblyopia. We will use sophisticated optical simulations to test hypotheses about motor and perceptual function when the motor visual system is unable to eliminate differences in retinal image quality or alignment.