Normal visual function requires that the eye can be adjusted to see near and far, have simultaneous binocular vision, stereopsis, and no abnormal retinal correspondence or diplopia. If there is an abnormality in binocular vision function that may lead to loss of focus, the cause of the lesion may be a disease of the nerve conduction pathway in the regulation process or a disease of the ciliary muscle used for eye regulation. The first step is to perform a brain examination, especially to rule out tumors and other diseases that compress or irritate the nerves, and to provide early treatment to avoid irreversible adjustment disorders. To rule out brain disease, an ophthalmologic examination should be performed, for example, for fusion dysfunction, stereopsis dysfunction, optometry, and synoptic examination can be an important adjunct. In addition ciliary muscle lesions, which may be inflammatory, traumatic, or occupying lesions, need to be treated for the cause.