Abstract

As with many other visual functions, ocular accommodation and vergence show rapid development in the first 6 months of life.¹-⁶ When convergence and accommodation are measured separately on the same child, evidence suggests that the two systems are not correlated in their responses until at least 2 months of age.⁷,⁸ There is little information on the early development of the cross links between accommodation and vergence, specifically accommodative vergence and vergence-driven accommodation. One study has been conducted on the development of accommodative vergence.⁹ In that study, Aslin and Jackson found convergence could be elicited when infants between 2 and 6 months of age monocularly viewed a target that was changing in depth. Although this is strong evidence for the existence of accommodative-driven vergence, the possibility remains that vergence was driven by proximity cues having different inputs than blur-driven accommodation.¹⁰ The purpose of our study was to determine if the convergence accommodation cross link was present in infants aged 3 to 6 months.

© 1997 Optical Society of America