noun. 1  a. An old French dance resembling the gavotte, usually in 3/4 or 2/2 time beginning with an upbeat. 2  A movement in ballet in which the dancer transfers body weight quickly from foot to foot, usually on the balls of the feet, in a series of small steps.
Nystagmus is a condition where the eyes make repetitive movements. The eyes can jerk exclusively in one direction, or make back and forth movements. With nystagmus, the eye can look jittery and can affect both eyes or just one eye.
Symptoms & Signs. Dilation, or widening, of the pupils of the eyes is normal in conditions of low light in order to allow more light to reach the retina. Medically, dilation of the pupils is known as mydriasis. Specific medications known as mydriatics are administered to dilate the pupils for ophthalmologic examination.