Eyeball deflection

There are many types of strabismus. The most common one is the inward deflection of the eyeball. Medically it is called esotropia, commonly known as "opposing eyes" and "cross-eying." The eyeballs are deflected outwards, called exotropia, commonly known as "squint eyes." Of course, strabismus does not only refer to the situation where the relative position of the two eyes is obviously deformed, but also includes cases where the slope is small, the surface is not easy to detect, and the binocular vision is abnormal, and also includes those cases where there is no strabismus at all but the eyes are abnormal . Therefore, the concept of strabismus should be understood as the abnormality of the two eyes' relative position and binocular function.