Why do children only squint sometimes?

In order for children to perceive things and objects correctly in space, both eyes must be directed directly parallel to the same object. An image can then be generated in both eyes that is slightly different from that of the other. This slight deviation is then processed further in the brain into a single visual impression.

When a child squints, the visual axis of the affected eye deviates temporarily or always from the object to be fixed, so that the information that is sent from this eye to the brain is too different from the other eye. The impressions cannot be processed. In children, the image perception of the cross-eyed eye is suppressed and weakness of vision often develops unnoticed.

It is important to distinguish between manifest and latent strabismus. With manifest strabismus, the affected eye constantly deviates from the common direction of vision. In most cases, this is caused by congenital visual disorders or newly occurring paralysis of the eye muscles.

Latent strabismus occurs more frequently in children. In this case, the squinting eye deviates only temporarily from the common line of vision. The causal disorder lies in an imbalance of the eye muscles, which, however, can be corrected at times. In the affected children the strabismus is only sometimes noticed and it remains hidden. Therefore, there is a risk that the strabismus is often noticed very late, when the affected eye already has weak vision.Latent strabismus is often aggravated by stress, concentration difficulties or increased fatigue.

Symptoms

Typical for strabismus is the unusual line of sight, which is often already noticed by parents. Usually, cross-eyed children squint their eyes together or even cover one eye with one hand to minimize double vision. If the child repeatedly holds his or her head at an angle, reacts irritably or moves awkwardly, this can also indicate strabismus, as strabismus severely impairs the child’s three-dimensional perception.

This is because both eyes have to look in the same direction so that the surroundings can be recognized as space. The two images seen by the right and left eye are combined in the brain to form a complete picture. In a cross-eyed person, these two images differ from each other in such a way that they no longer match and the brain cannot bring them together into a single image. Instead, the child sees double images. If this condition lasts longer, the brain “switches off” the visual impressions of the cross-eyed eye and the child then only sees with the healthy eye, but still not in 3D.