![]() There are two key forms of nystagmus: pathological and physiological, with variations within each type. The direction of ocular movement is related to the semicircular canal that is being stimulated. Nystagmus occurs when the semicircular canals are stimulated (e.g., by means of the caloric test, or by disease) while the head is stationary. From here, a signal is relayed to the extraocular muscles to allow one's gaze to fix on an object as the head moves. The semicircular canals in the vestibule of the ear sense angular acceleration, and send signals to the nuclei for eye movement in the brain. In normal eyesight, while the head rotates about an axis, distant visual images are sustained by rotating eyes in the opposite direction of the respective axis. In many cases it may result in reduced or limited vision. People can be born with it but more commonly acquire it in infancy or later in life. ![]() Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement, sometimes informally called "dancing eyes". ![]() ![]() Horizontal optokinetic nystagmus, a normal ( physiological) form of nystagmus ![]()
0 Comments
Leave a Reply. |