What causes squint in children?

Children always have problems when they are young due to some habits or congenital conditions, and many parents become worried at this time. Among them, there are cases where children have strabismus when they are young. Because we don’t know what is going on, we cannot treat it well. So parents want to know why children have strabismus. Let’s take a look at it together, hoping to give children the possibility of correcting their vision in advance.

1. Congenital abnormalities: This type of strabismus is mostly caused by congenital abnormalities in the position and development of the extraocular muscles, abnormal development of the extraocular muscles themselves, incomplete differentiation of the mesoderm, poor separation of the eye muscles, abnormal muscle sheaths and fibrosis, and other anatomical defects or paralysis of the nerves that control the muscles. Some cases are due to head and facial injuries caused by the use of forceps during delivery, or the mother's excessive force during delivery, which leads to increased intracranial pressure in the fetus and causes punctate hemorrhage in the brain. The bleeding happens to be in the nerve nucleus that controls eye movement, causing paralysis of the extraocular muscles. In addition, there are also genetic factors. Strabismus is not inherited by all members of the family. This defect is often indirectly passed on to the next generation of children. Generally, strabismus that occurs within 6 months after birth is called congenital strabismus. It does not have the basic conditions for establishing binocular vision and has the greatest harm to the development of visual function.

2. Imperfect development: Children, especially infants and young children, have imperfect binocular vision function and cannot coordinate the extraocular muscles well. Any unstable factors can lead to the occurrence of strabismus. Human's monocular vision function is gradually developed after birth. Just like the visual function, this function is established by repeatedly receiving stimulation from clear external images, and gradually develops and matures. Infants only have gross fusion image 2 months after birth, and the establishment of precise fusion image function will continue until after 5 years old. Stereoscopic vision is established at the latest, and it is close to that of adults at 6 to 7 years old. Therefore, the period before the age of 5 when binocular single vision function is not yet perfect is a high incidence period of strabismus in children.

3. Eye development: Children have small eyeballs and short eye axes, so they are mostly farsighted. Also, children have strong corneal and lens refractive power and strong ciliary muscle contraction, that is, strong accommodation power. Such children need more accommodation power to see objects clearly. At the same time, their eyes turn inward forcefully, resulting in excessive convergence, which can easily cause esotropia, a type of esotropia called accommodative esotropia.

4. Insufficient control ability of the eye movement center: If the convergence is too strong or the abduction is insufficient, or both exist at the same time, esotropia will occur; conversely, if the abduction is too strong, the convergence is insufficient, or both exist at the same time, exotropia will occur.

Through the content above, I believe everyone has a general understanding of the reasons why children have strabismus. The most important thing is that it has a lot to do with the child’s development, so it should be treated as early as possible. Once parents find that their child has any abnormality, they must take the child to the hospital for treatment as soon as possible to ensure the child's health.