Cock-eyedness is a medical term for internal strabismus. If a baby is less than 6 months old and has crossed eyes, no intervention is usually given. However, if your baby is still cross-eyed after 6 months of age, you should pay attention to the possibility of internal strabismus, and parents are advised to take your baby to the doctor for examination in time. A. How to identify crossed eyes When a normal person looks at an object directly in front of him or her, the centers of the pupils on both sides should be in the same position. However, more obvious internal strabismus can be detected by direct observation. For non-obvious crossed eyes, parents can shine a flashlight on the bridge of the baby’s nose and encourage the baby to look into the flashlight. If the reflective spot of one eye appears outside the center of the pupil, it indicates the presence of strabismus; or take a few pictures of the baby looking directly into the camera. If parents are unable to determine the presence of crossed eyes through self-examination, they can take their baby to the hospital to see a professional doctor to confirm the condition. The doctor will usually ask whether the baby has been treated for amblyopia, whether there is a family history of amblyopia, as well as perform visual acuity examinations, refractive examinations, routine external eye, anterior segment and fundus examinations, and, if necessary, specialized examinations such as oculomotor function and binocular visual function to confirm the diagnosis. Second, how to treat crossed eyes Because internal strabismus can affect the facial image and the psychological health of the child, resulting in permanent amblyopia, stereo vision deficiency, i.e., the depth and distance of the visible objects obtained by binocular vision, it is necessary to actively intervene. Parents can adjust the infant’s eye habits, such as moving toys directly in front of the eye to the outside of the affected eye, or keeping the baby away from the TV and arranging more recreational activities for him/her. Depending on the type and degree of strabismus, the doctor may choose to treat the child, for example, if there is a large difference in refraction between the two eyes or poor vision in one eye, the child may be allowed to wear an eye patch. If the child has a moderate strabismus or a combination of moderate to high refractive abnormalities, it can be corrected with appropriate glasses. Most children with congenital internal strabismus and upward and downward strabismus require surgical treatment, in which the strength of the external eye muscles and the position of the attachment points are adjusted to normalize the eye position, thus achieving the goal of treatment.