fixational eye movements
Miniature eye movements that occur during attempted fixation, including microsaccades, drift, and tremor.
Full Definition
Fixational eye movements are small involuntary movements that occur even when attempting to maintain steady fixation on a target. These include microsaccades (small rapid movements), ocular drift (slow wandering movements), and ocular tremor (high-frequency oscillations). These movements are essential for preventing visual fading and maintaining visual acuity, but abnormalities can indicate neurological dysfunction. Assessment of fixational stability is important in neuro-ophthalmological evaluation, particularly when investigating complaints of oscillopsia or visual instability.
Usage
Usage note: Normal phenomenon that can become pathological in certain conditions.
In Context
- "Analysis of fixational eye movements revealed increased drift consistent with cerebellar dysfunction." — eye movement laboratory report
- "The patient's oscillopsia correlated with abnormal fixational eye movements on video-oculography." — neuro-ophthalmology consultation