Zivotofsky, A. Caspi, R. Previous studies Ciuffreda, have shown that subjects are capable of superimposing voluntary nystagmus on slow eye movements that track a smoothly moving target.
Nystagmus is a medical condition in which the eyes move involuntarily, often shaking back and forth. These involuntary movements may be horizontal, vertical, or sometimes even rotational. The movements may be very subtle, very prominent, or somewhere in between. They can be fast or slow. They usually affect both eyes. Nystagmus itself is not a diagnosis -- it is a sign of another disease. Nystagmus in children is caused by three different categories of disease:. People with nystagmus due to eye problems have abnormal vision, and this decreased visual ability causes the eyes to shake. Ocular causes of nystagmus include childhood cataracts, optic nerve developmental problems, and genetic retinal diseases like Leber congenital amaurosis, albinism, retinitis pigmentosa, or achromatopsia, among others.
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Timothy C. Hain, MD. This can be spotted because the pupil constricts during the convergence effort. This is usually considered a "party trick", and not a disease at all. Only a few papers have been written with "voluntary nystagmus" in their title 46 as of This is usually a brief high frequency horizontal shimmer, that cannot be sustained for more than about 5 seconds. Occasional persons also appear to be able to produce voluntary multidirectional eye movements resembling opsoclonus. While there are a few other types of nystagmus under voluntary control, such as some variants of congenital nystagmus , for the most part, the term voluntary nystagmus is reserved for this group. Supplemental material : Video of voluntary nystagmus. Supplemental material : Another video of voluntary nystagmus.
Generally, no. You can think of nystagmus as an abnormal ocular reflex, just like the reflexes doctors check in your arms and legs. The abnormal reflex on its own isn't usually a problem, but it sometimes indicates that there has been damage to the brain or spinal cord, which is what the doctor is looking for when he or she tests for nystagmus. So nystagmus itself isn't really a disease, but it is often a sign of disease or damage.