Crossed eyes are known as strabismus in the medical field and this condition involves the eyes looking at different places in the same moment. Those with crossed eyes will notice one eye looking right at the object they are viewing, but the other eye will be misaligned, either being downward, upward, outward, or inward. The American Association for Pediatric Ophthalmology and Strabismus estimates that around 4 percent of Americans have a cross eye or some other form of strabismus. Although strabismus is most common among young children or infants, it may occur at all ages. It affects girls and boys equally and affects up to five percent of kids.

What Causes Crossed Eyes?

Every eye features six externalmuscles which are responsible for controlling its movement and position. In order to have normal binocular vision, it is necessary for the muscles within each eye to be perfectly coordinated, including their functioning, neurological control, and position.

• Cross eyed vision takes place if anatomical or neurological issues interfere with the function or control of these extraocular muscles. This problem might originate within the muscles themselves or it can occur within the vision centers or nerves of the brain responsible for controlling binocular vision.
• Genetics can also affect whether a person has crossed eyes. Children are more likely to develop strabismus if at least one parent has it.
• In some cases, strabismus will be linked to specific illnesses, including thyroid disorders, myasthenia gravis, multiple sclerosis, high blood pressure, or diabetes.

Note: It Can Be Normal in Infants

It is common for parents to notice that their infant’s eyes wander occasionally within their first few months. This is simply due to the fact that the infant is in the process of learning how to focus his/her eyes and move them together.

This intermittent strabismus in infants is part of normal development, typically disappearing before they reach three months old. The other forms of crossed eyes, however, will not disappear unless they are treated.

Types of Crossed Eyes and Signs of Being Cross Eyed

Strabismus may be intermittent (occurring sometimes) or constant (occurring all the time). It is possible for intermittent strabismus to worsen if the eye muscles become tired, such as when a person is sick or later in the day.

Some of the most common symptoms of having crossed eyes include:

• Double vision
• Faulty depth perception
• Tilting the head when looking at things
• Frequent squinting or blinking, particularly in bright light
• Eyes that don’t seem to move together
• Eyes that seem misaligned

To classify strabismus, experts look at the misalignment direction. If one eye looks straight ahead, the other may turn in towards the nose (convergent or esotropia), outward towards the ear (divergent or exotropia), upward (hypertropia), or downward (hypotropia).

The most common of these types is esotropia and there are several varieties of it:

• Infantile esotropia appears at birth or occurs within a person’s first six months. In many cases, there will be a family history for strabismus. The majority of children with this form will be otherwise healthy, but the disorder does occur in a high incidence with hydrocephalus and cerebral palsy.
• Accommodative esotropia occurs in children with extreme farsightedness. In this case, the crossed eyes occur because the child has issues focusing on objects nearby. Parents may notice that their child’s eyes turn in, particularly when he/she concentrates on an object that is close. This tends to be diagnosed at age 2 or 3 and is linked to family history.

Note: It Can Be Pseudoesotropia

This can seem like strabismus but is different. In this condition, there is an extra skinfold or widened nasal bridge that makes it harder to see the white sclera on the side of the eye closest to the nose. This makes a person seem cross eyed and will typically disappear as facial structures change and the infant grows.

When to Talk to a Professional

As soon as you have any concerns about the alignment of your child’s eyes or the ability to see properly, you should contact the health care professional. A pediatric ophthalmologist will need to evaluate a child with constant strabismus no matter the age or one with intermittent strabismus lasting past three months of age.

Adults who develop signs of strabismus such as double vision should contact their healthcare professional for an evaluation.

How to Treat Crossed Eyes

The goal of treating a cross eyed patient is to restore or preserve the maximum amount of visual function. The treatment will vary based on the cause and type of strabismus.

• Glasses may correct vision within the weaker eye or a child may be forced to wear a patch over their dominant eye as a method of making them use their suppressed or weaker eye.
• Eye drops may also temporarily blur the preferred eye’s vision for the same reason.
• There are also exercises that can strengthen particular eye muscles and the act of forcing children to use their weaker eye may reinforce the link between the brain and eye, improving sight.
• To realign the eyes, cross eye surgery is required that will loosen or tighten particular eye muscles. This is a quick operation and is done with general anesthesia. It may include both eyes or just one and sometimes multiple surgeries will be required.

Crossed Eyes Are Not the Same Thing as Lazy Eyes

It is common to mistakenly refer to a crossed eye or strabismus as amblyopia or a lazy eye. This term refers to decreased vision in both or one eye. It is possible, however, for strabismus to lead to amblyopia. This occurs because misaligned eyes cause the brain to receive two images which are different, leading to double vision.

If the patient is a young child, their visual system is not yet fully mature, meaning the brain can suppress the image coming from one eye, avoiding double vision. If the vision related to one eye gets consistently suppressed, the other eye may become dominant, leading to amblyopia. This is why cross eye treatment is very important.

Between a third and half of children with strabismus develop amblyopia. Strabismus is usually fairly obvious, but doctor confirmation is necessary to diagnose amblyopia.