Voluntary Flutter (Voluntary “Nystagmus”)
Voluntary “nystagmus” consists of rapidly oscillating eye movements (almost always horizontal) that can be induced volitionally. These movements, which are not a form of nystagmus (because they lack slow phases), appear as high-frequency, conjugate, back-to-back saccades without an intersaccadic interval. They are associated with convergence, facial grimacing, and eyelid fluttering. Episodes are unsustained, rarely lasting longer than 30 seconds. Voluntary nystagmus occurs in 8% of the normal population, may be familial, and is not associated with other neurological findings. At times, voluntary nystagmus can be difficult to distinguish from ocular flutter. Unlike voluntary nystagmus, ocular flutter may be sustained; is typically associated with other neurological signs (such as ocular dysmetria, ataxia, and myoclonus); and does not have the convergence, facial grimacing, and eyelid fluttering of voluntary nystagmus.
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.