Accommodation and Defocus in the Infant Visual System

Project Summary/Abstract:
Postnatal development of the human visual system is dependent on visual experience. Abnormal visual
experience during infancy and childhood can lead to strabismic misalignment of the eyes and
amblyopia. The goal of the proposed research is to understand how the visual system uses its available
natural experience to coordinate eye alignment and focus during infancy and early childhood, in the
context of prevention of these clinical conditions. There are two interrelated projects:
i) To understand how depth information across the visual field can be used to coordinate eye alignment
and focus during early postnatal development, and how common clinical disorders during early
childhood can disrupt that coordination.
ii) To understand which image structure across the visual field is capable of driving a conjugate
orienting eye movement during early postnatal development, and how the binocular aspects of that
movement can be disrupted by common clinical disorders.
These projects will test hypotheses and build models to determine the amounts of conditions such as
anisometropia that can disrupt ocular motor control as a function of human postnatal age. Previous
studies of the development of focusing accommodation responses and aligning vergence responses
have concentrated on 2D stimuli in the central visual field, while the brain needs to function in the full
field, dynamic, three-dimensional natural environment in order for a patient to develop typical vision. It
is the interaction between this visual environment and the quality of retinal visual experience that motor
control can provide that defines a patient’s experience-dependent development. The results will
provide i) evidence-based clinical guidelines for the prevention of amblyopia and strabismus ii)
constraints for biologically-inspired simulations of the development of vision.

Grant Number: 5R01EY014460-22
NIH Institute/Center: NIH
Principal Investigator: T CANDY