The term cross-eyed comes from the Latin word versĭcus, derived from versus (which can be translated as “returned”). It is said that someone is cross-eyed when they have strabismus: an abnormal arrangement of the eyes that causes the visual axes to not focus simultaneously in the same place.

A cross-eyed or squint subject, therefore, does not have the eyes aligned with each other. In this way, the binocular vision of the person is deficient since it is not possible to fix both eyes in the same point, a particularity that translates into inconveniences to perceive depth.

A human being can be born cross-eyed or acquire strabismus over the years. If the individual is congenitally strabismic or develops the condition in childhood, they may suffer from amblyopia. This visual disorder causes the neurological structures related to vision to not develop properly, making it impossible to correct strabismus.

With regard to what happens so that the eyes of a cross-eyed subject do not have the normal alignment, it is a lack of coordination between the six muscles that are around each eye, which should always work together to achieve the focus of the objects. As stated above, a cross-eyed person has difficulty getting both eyes looking at the same object.

This behavior on the part of the eyes means that the brain receives two different images, with different objects in focus, and then cannot process them clearly. During childhood, the brain can be trained to ignore or suppress the image coming from the less strong eye.

To determine if a child is cross-eyed and to discover which is the eye with fixation problems, tests of coverage (covering one eye at a time) and light reflection in the cornea are carried out.

According to DigoPaul, a cross-eyed person can be treated through the use of optical prisms, spectacles (goggles), or patches. You can also appeal to a surgical intervention. Certain exercises, on the other hand, can help correct strabismus.

The cause of strabismus is very difficult to determine, and in fact it is unknown in most cases. Congenital strabismus, which appears at birth or a short time later, is the most common of all. It is worth mentioning that the problem usually does not lie in a lack of strength in the muscle, but in the inability to control it.

In adults, the causes of strabismus are associated with different problems: diabetes (which leads to the disorder known as acquired paralytic strabismus), Graves’ disease, botulism, an eye injury, Guillain-Barré syndrome, an accident cerebrovascular disease, shellfish poisoning, vision loss, or traumatic brain injury.

On the other hand, if someone in the family suffers from strabismus, then this increases the chances that the descendants will acquire it. In general, any illness or injury that affects vision can become a contributing factor. In children, for example, one of the conditions that can lead to crossed eyes is hyperopia (difficulty seeing close objects with the same clarity as distant ones).

It is important to note that the symptoms of strabismus, such as difficulty in perceiving depth or differences in alignment between the eyes, are not always constant, meaning that in some cases they appear intermittently. In addition, it is normal that cross-eyed children are not aware of their problem, because of the work that the brain does to compensate for the imprecision of the information.

Penelope Cruz, Barbra Streisand, Andy Garcia and Kate Moss are some of the famous cross-eyed. As can be seen, strabismus is not a disabling condition nor does it prevent reaching public notoriety.