ocular apraxia
Impaired ability to voluntarily direct gaze to specific visual targets despite preserved eye movement mechanics.
Full Definition
Ocular apraxia, also known as psychic paralysis of gaze, is a disorder of voluntary eye movement control characterized by difficulty in directing gaze to specific targets on command, despite preserved ability to follow moving objects and intact oculomotor reflexes. This condition represents a breakdown in the voluntary control systems for saccadic eye movements, typically resulting from lesions affecting the frontal eye fields or their connections to brainstem oculomotor centers. Patients with ocular apraxia may use head movements or blinking strategies to help redirect gaze, and often show preserved smooth pursuit movements. The condition is frequently seen as part of Balint's syndrome, particularly following bilateral parietal-occipital lesions. Assessment involves testing voluntary saccades to command while monitoring compensatory strategies and preserved automatic eye movements.
Usage
Usage note: Distinguish from mechanical eye movement disorders by testing both voluntary and reflexive movements.
In Context
- "The patient's ocular apraxia required her to turn her entire head to look at objects, as voluntary eye movements were severely impaired." — Oculomotor examination report
- "Ocular apraxia was evident in the patient's inability to look toward named objects despite preserved ability to track moving targets." — Balint's syndrome assessment