External strabismus may be caused by abnormal development of eye nerves, muscles and ligaments, refractive error, mental and other factors, and can be corrected and trained through the use of special corrective devices, visual acuity training method, monocular cover method and other ways. 1. Use of specialized corrective devices: Corrective training can be carried out by wearing specialized corrective glasses or using prisms. 2. Visual acuity training: Corrective training through threading beads, threading needle and thread, pen-tip method, multimedia CD-ROM method, etc. can help to alleviate the symptoms of blurred vision and strabismus. 3. Monocular masking method: masking the normal eye and forcing to use the strabismic eye to see can help to reduce the symptoms of strabismus. There are many other ways to correct strabismus, it is recommended to go to a regular hospital and train under the guidance of a doctor in order to achieve the best corrective effect.