Did you know that congenital cataracts, congenital glaucoma, etc. can cause “congenital nystagmus” and that if the eyeballs swing back and forth to the left and right or up and down, there is a good chance that you have “nystagmus”? It is also hereditary, so early detection and diagnosis are especially important. The frequency of nystagmus is the same in both eyes. Congenital nystagmus is an involuntary, rhythmic, pendulum-like or pulsating oscillation of the eyeballs, and the amplitude and frequency of nystagmus are usually the same in both eyes, regardless of whether one eye is covered or both eyes are opened. Congenital nystagmus is rarely detected at birth and is usually detected after 3-4 months of age. This disorder can adversely affect the normal development of vision during childhood and can cause more severe amblyopia in particular. Although the eyes of a person with congenital nystagmus are constantly in motion, there is no sense of swaying, only the perception of objects moving in a certain direction. Strabismus is also a common complication, with approximately 20% of patients suffering from combined strabismus. Nystagmus can even cause asymmetrical facial development, mainly in the form of left or right facial deflection, which can have a significant impact on the appearance of the patient. Some cases of nystagmus are caused by abnormalities in the eye, so early detection and diagnosis is especially important. When nystagmus is detected, it is important to go to the hospital for examination to rule out organic eye diseases such as congenital cataract, congenital glaucoma, and treatable diseases such as pediatric hereditary fundus disease. Before the age of two, infants and young children must restore the clarity of visual pathways and promote their visual development. If there is refractive error, glasses should be worn to prevent the formation of severe amblyopia. In addition, congenital nystagmus can also be treated surgically, with different surgical approaches designed for different patients. The degree of nystagmus can be traced by nystagmography before and after the surgery, and weak nystagmus that cannot be detected under the naked eye can be detected. Only early treatment of the primary disease and active treatment of amblyopia can improve visual acuity.