Many parents of nystagmus ask experts why my baby has nystagmus, which is summarized as the following two causes: Cause 1: Some scholars believe that congenital nystagmus is a failure of the sfoweyemovements control subsystem, which is active under abnormal conditions of high gain, and this particular abnormality may be manifested by the extraocular muscles proprioceptive This particular abnormality may be manifested by the feedback of the signals about eye position and movement speed from the receptors, which results in an unstable eye position and deviation of the eye from the positive position, which constitutes the slow phase of the tremor, and a fast sweeping movement that interrupts this slow phase and returns to the gaze position, which constitutes the fast phase of the tremor. Cause 2: Other scholars believe that the defect in the subcortical optokinetic system causes the eye to deviate from the gaze position due to the instability of the gaze, and that correcting the eye movement brings the eye back to the gaze position. Recent studies by Dell’osso et al, a leading nystagmus expert, have shown that patients with congenital nystagmus have a strong fixation reflex, normal smoothpursultmotion, and good vestibular glance reflex function. They concluded that although the exact function of the impulses to the proprioceptors of the extraocular muscles is not known, it has an effect on both eye position and velocity in the feedback loop, and therefore congenital nystagmus may be due to instability in the peripheral part of these feedback loops. The details of the pathogenesis of congenital nystagmus need to be further investigated. Since the control of eye movements is a circular feedback mechanism, multiple links can control eye movements, including the structure of the eye, afferent pathways, diseases of the central brain, and diseases affecting vestibular function can cause nystagmus; for example, visual impairment nystagmus, otogenic nystagmus, and central nystagmus. Although it is not a common or frequent disease, it is not uncommon in clinical practice and can seriously affect the visual function, appearance, and mobility of patients. The pathogenesis of nystagmus is very complex and is still inconclusive. What is a proprioceptor? One of the main surgical procedures for nystagmus is the removal of the proprioceptors. Why does the removal of proprioceptors improve nystagmus? The proprioceptors are receptors located within muscles, tendons and joints that sense changes in body movement and position in space and provide information to the center. When the eye moves, the mechanical stretching of the muscle and tendon becomes a suitable stimulus for the proprioceptors, and the degree of stretching is transmitted to the center. Dr. Bai Dayong (deputy head of the nystagmus treatment team at Beijing Children’s Hospital): Through current international basic and clinical research, it has been found that removal of the proprioceptors can improve the frequency and amplitude of nystagmus to some extent without causing any serious complications in children, and has become a mainstream surgical procedure for the treatment of nystagmus.