Seventy-five infants of state-registered orthoptists were observed by their mothers from birth to at least 6 months of age, with particular attention paid to the nature of any deviations noticed in the first few weeks. Most of the infants showed brief periods of inaccurate vergence during the first 2 months, with a wide variation in the amount of deviation seen, despite going on to develop normal binocular single vision. Most deviations were transient, unilateral, alternating esodeviations. There was a statistically significant relationship between the time that deviations were noticed and the development of demonstrable binocular convergence. Few exodeviations were found, contrasting with previous studies, and it is suggested that neonates are more likely to achieve binocular single vision when interacting with their mothers.