Strabismus and amblyopia are common and frequent diseases in ophthalmology, with a prevalence of 3% and 2% to 4% respectively. This specialty is an important part of ophthalmology and intersects with optometry, neuro-ophthalmology and pediatric ophthalmology. The common term “crossed eyes” is a kind of strabismus, so strabismus can be approximated as a skewed position of the two eyes. To be complete, the concept of strabismus should be understood as an abnormality in both the relative position of the two eyes and the visual function of both eyes. Strabismus has existed since humans developed binocular vision, but humans recognized the phenomenon relatively late. Binocular vision means that an object from the outside world is imaged on the retina of both eyes, generating nerve impulses that are transmitted to the brain, where the higher centers analyze the visual signals from both eyes and synthesize them into a complete, three-dimensional image. In essence, strabismus is a disorder of binocular vision. Pediatric strabismus can often cause amblyopia, and this strabismic amblyopia, if not treated promptly and appropriately, will lead to permanent damage to vision, and strabismus can also affect the development and establishment of binocular vision function. Strabismus is common in adults, some of whom develop it in adulthood, but an even larger proportion already develop it in childhood. In addition to causing damage to visual function in one and both eyes, it also affects appearance and cosmetology, which can have a negative impact on the child’s physical and psychological development and growth.