Low-luminance myopia and dark vergence

In normal binocular vision, under photopic conditions, accommodation and convergence act in synergy. We examined the relationship between these two functions in darkness, in the absence of all accommodative and fusional stimuli. Accommodation was measured as it is expressed in low-luminance myopia. There was no strong positive correlation between accommodation and vergence in darkness. Rather, the two systems were dissociated, and appeared to assume independent resting states with accommodation generally exceeding convergence.