negative convergence

convergence /con·ver·gence/ (kon-ver´jens)

1. in evolution, the development of similar structures or organisms in unrelated taxa.

2. in embryology, the movement of cells from the periphery to the midline in gastrulation.

3. coordinated inclination of the two lines of sight towards their common point of fixation, or that point itself.

4. the exciting of a single sensory neuron by incoming impulses from multiple other neurons.conver´gent

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negative convergence  outward deviation of the visual axes.

positive convergence  inward deviation of the visual axes.

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negative convergence

n.

The outward divergence of the visual axes when the eyes are not required to be convergent, as when looking at the far point of normal vision or during sleep.

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divergence

1. Movement of the eyes turning away from each other. 2. Characteristic of a pencil of light rays, as when emanating from a point source. Syn. negative convergence. See vergence.
divergence excess A high exophoria at distance associated with a much lower exophoria at near. It may occasionally give rise to diplopia in distance vision.
fusional divergence A movement of the eyes away from each other in response to retinal disparity, in order to restore single binocular vision. It occurs most commonly when induced by a base-in prism.
divergence insufficiency A high esophoria at distance associated with esophoria at near. It often gives rise to symptoms of asthenopia in both distance and near vision.
divergence paralysis See divergence paralysis.
vertical divergence Relative vertical movement between the two eyes.