Internal strabismus is clinically classified into congenital internal strabismus, acquired internal strabismus, secondary internal strabismus, and others, such as internal occlusion, etc. In the case of internal strabismus, the first step is to do a refractive state examination. For people under 40 years old, a medical dilated eye examination should be done, and if the diagnosis is related to hyperopia and the degree is obvious, adequate correction should be done. If the degree is relatively large, trigeminal correction can be considered; surgical treatment is generally not considered unless the strabismus is greater than 12 degrees or more. In the case of congenital internal strabismus, it usually occurs within six months after birth. The first step is to prevent the occurrence of amblyopia. The next step is to correct the eye position so that the strabismus at near and far is reduced and is close to the ortho-position, or at least perceptual fusion can be achieved. It is generally believed that surgery before the age of two is more effective. For acquired internal strabismus and partially adjusted internal strabismus, refractive correction is considered first, and then surgery is considered if it cannot be corrected by glasses. If the strabismus is acute common, first of all, you should go to the neurology department for examination to exclude cranio-cerebral diseases. If the strabismus is large and the diplopia does not interfere much, you can temporarily observe and conservative treatment first, or correct the refractive error; if the strabismus is large and the symptoms are stable, you can consider surgery for correction.