To confirm the diagnosis of strabismus, in addition to checking the eye position and the angle of strabismus, we also need to do eye movement examination and binocular visual function examination. The eye movement examination is to check the strength of the extraocular muscles, to determine the coordination of the extraocular muscles, and to check if the extraocular muscles are causing the strabismus. During the examination, one eye is covered and the other eye is looking at an object in the doctor’s hand. The eyeballs follow the object in the doctor’s hand by turning left, right, up and down, as well as turning left up, right up, left down and right down. Normal eye movements have a certain amplitude and can reach a certain position in all directions. When the eye movements in a certain direction cannot reach the normal position, or when nystagmus occurs when the normal position is about to be reached, it indicates that the muscle strength is insufficient; while eye movements exceeding the normal position indicate that the muscle strength is hyperactive. After that, binocular gaze examination was performed simultaneously, and the practice and judgment of the results were the same as monocular examination. Binocular visual function is mainly examined by various stereoscopic examination charts and synoptic machines, including far and near stereoscopic vision examination, which is to know whether the two eyes of the child can fuse the objects seen together and whether the objects seen have stereoscopic sensation, which provides an important reference index for choosing the timing of surgery. In addition, refractive and funduscopic examinations will be performed. Refractive examination to see if the child is farsighted or nearsighted, etc. This examination usually requires pupil dilation, and if there is a refractive problem, refraction needs to be treated first, followed by treatment of strabismus. A fundus examination can rule out strabismus caused by diseases of the fundus of the eye. The tests to confirm strabismus require the child’s cooperation. Parents should try to communicate with the child in advance, telling him that there is no pain and no needles in the office, so that the child will be less nervous and will be able to cooperate with the doctor’s requirements. If the child does not cooperate with the examination, the doctor will only be able to determine whether there is strabismus or not, but will not be able to make a detailed diagnosis, and will not be able to formulate a precise treatment.