optic ataxia
Pronunciation: OP-tik ah-TAX-ee-ah
Inability to accurately reach for visually guided targets despite normal vision and motor function.
Full Definition
Optic ataxia is a visuomotor disorder characterized by the inability to accurately reach for or point to objects under visual guidance, despite having normal visual acuity and motor strength. This condition results from a disconnection between visual processing and motor planning systems, typically associated with bilateral parietal-occipital lesions, particularly in the posterior parietal cortex. Patients show normal reaching when using proprioceptive cues but demonstrate significant errors in visually guided movements. Optic ataxia is one of the three components of Balint's syndrome, along with simultagnosia and psychic paralysis of gaze. The condition severely impacts daily activities requiring visual-motor coordination.
Usage
Usage note: Test both peripheral and central visual fields; may be field-specific in some cases.
In Context
- "Optic ataxia was demonstrated by the patient's inability to touch the examiner's finger accurately." — Visuomotor assessment documentation
- "Despite normal vision and strength, optic ataxia prevented accurate reaching for objects." — Balint's syndrome evaluation