Crossed eyes (esotropia)
Esotropia is eye-doctor lingo for crossed eyes that turn toward the nose. This kind of eye crossing is a strabismus, or misalignment in the visual system.
The condition is problematic because, for vision to work, the eyes need to line up correctly. Each eye splits the visual field in two, then the brain puts these two halves back together and creates eyesight.
Sometimes, though, the six muscles controlling each eyeball get fouled up, knocking the eyes out of alignment. When that happens, the brain has a hard time making sense of the visual information it’s getting. This can produce double vision or blurry vision that has to be corrected by an eye doctor.
Esotropia is more common in babies and young children, but it can happen at any age. Sometimes the condition runs in families.
There are also different types, including accommodative esotropia, where eye crossing is caused by the focusing efforts of the eyes as they try to see clearly, or intermittent esotropia, in which crossed eyes come and go.
Esotropia: a definition
Esotropia is specific to crossed eyes (one or both) that turn toward the nose. Pronounced “ee-so-TROE-pee-ah,” the name arises from the Greek terms “eso” (inward) and “trope” (turn).
Doctors use different terms when the eyes get misaligned in other directions:
Exotropia — outward turning (also called wall-eyed)
Hypertropia — upward turning eyes
Hypotropia — downward turning eyes
Remember, these are all varieties of strabismus, the umbrella term for visual misalignment. Like esotropia, each one poses distinct treatment challenges, which is why doctors need separate and defined terms.
Types of crossed eyes
Eyes can become misaligned for various reasons, including underlying health issues, or trying too hard to accommodate a different vision challenge, such as farsightedness in only one eye.
The various kinds of esotropia can be determined by an eye doctor, but generally depend on factors such as age, the ways in which the eyes cross, and even how the brain responds to stimuli.
Some key types include infantile esotropia, which affects babies — even babies with good vision — and could lead to future problems if not addressed early.
Constant, intermittent and alternating esotropia
Eye crossing can be constant — that is, the same eye (or eyes) stay crossed the same way — or intermittent, which is when crossed eyes come and go. You can even have alternating esotropia, which switches from one eye to the other.
These conditions create confusion in the brain, leading to headaches, double vision, eye strain and other symptoms.
Babies are often born with crossed eyes. This usually resolves on its own within the first three months of life, with no treatment needed at all.
Infantile esotropia, however, refers to inward crossed eyes in the first six months. It’s sometimes called congenital esotropia and it requires more attention.
Infants born with esotropia typically have normal vision in each eye, but the trouble arises because the eyes are out of alignment and the brain can’t create a focused visual field. When this happens, the brain may direct more of its energy to translating the information from one eye, while ignoring visual signals from the other one. This weakens the other eye, possibly triggering a condition called lazy eye (amblyopia).
Occasionally, the shape of the nose and the eyelids will give the impression that a child is cross-eyed when in fact there is actually nothing wrong. This condition, called pseudostrabismus, requires a careful diagnosis because some children who look this way still do have an eye misalignment.
Babies are born with poor vision, which improves as they age. After six months, an infant’s eye development is closer to complete, so doctors adjust their strategies for crossed eyes after that point.
Sometimes, the act of bringing something into focus can cause the eyes to cross. A child with farsightedness in one eye, for instance, can have trouble getting their vision to cooperate with the other eye, which has normal vision.
This can be especially problematic in children because adjusting the angle of their eyes to “accommodate” visual challenges can damage their visual development. Doctors have many proven strategies for treating accommodative esotropia — regardless of the method, though, it’s crucial to treat it as early as possible.
Eyeglasses can frequently fix this type of esotropia. If eyeglasses don’t work, then the condition is called non-accommodative esotropia.
Treatment of esotropia
During a comprehensive exam, your eye doctor will usually talk to you about your family history, as esotropia can sometimes be hereditary. Other conditions and issues, including cerebral palsy, Down syndrome and strokes or head injury, might also mean a higher risk of developing esotropia.
Eye doctors also perform a series of tests to confirm that eye misalignment is actually esotropia. In one such test, the doctor will cover one eye and observe the movement of the other eye — if the uncovered eye turns inward, that points to esotropia.
Other eye tests determine whether the esotropia can accommodate corrective lenses, for patients with farsightedness, nearsightedness or astigmatism. In most cases, eye doctors will start with the least invasive treatment methods before trying procedures like esotropia surgery.
Eyeglasses can help most children who have accommodative esotropia. The doctor will determine whether single-vision or bifocal lenses are the best choice. Of course, the child will have to get a lot of training on choosing the right glasses and wearing them properly over time.
Keep in mind that eyeglasses at this stage are for getting the eyes into alignment. A child needs to be reminded to relax the eye muscles and let the glasses do their job. It may take weeks or months for the eyes to show improvement, so it’s important to keep encouraging the child to stick with it.
Over time, the child’s eyes will adapt and change, often requiring new prescriptions. So, it’s just as important for the parent to stick with it as well.
Cross-eyed adults pose a different challenge. Often, there’s an underlying disease or condition that knocks the eyes out of alignment. Eyeglasses or prisms might work with some people, but other options like vision therapy or surgery may be required.
Wearing an eye patch can help with lazy eye and other problems related to esotropia, both for children and adults.
Another tactic is to retrain the muscles to move back into alignment. A few of these exercises are available online, but it’s best to check with a doctor to see which ones have the best chance of success.
Procedures like Botox injections can offer an alternative to the next step, which is surgery. Botox causes paralysis in eye muscles that can last for a few months or might be permanent.
A surgeon may be able to correct some kinds of esotropia in children if less invasive methods like eyeglasses or vision therapy designed for kids prove ineffective.
In those cases, the eye muscles are out of balance. Stiffness or weakness causes some of the muscles to pull the eyeball out of alignment. The surgeon’s job is to loosen, tighten or adjust the muscles to align the eyeball correctly. It might have to be done in both eyes and could require multiple surgeries.
Strabismus surgery is not overly disruptive. Usually, it’s done on an outpatient basis and doesn’t require a lot of down time before getting back into everyday activities.
When to see an eye doctor
There’s no time to lose if your eyes get out of alignment. A doctor needs to check it out as soon as possible because the longer you wait, the harder esotropia is to fix.
The condition needs to be closely monitored in infants and children. While newborns may have esotropia that goes away naturally, cases in older babies and young children should be addressed quickly to avoid permanent damage.
It’s also important to check in regularly with your eye doctor, as crossed eyes could be a sign of another condition in the body like a tumor or thyroid malfunction, both of which are serious problems.
READ NEXT: What is esophoria?
Page published in January 2021
Page updated in October 2021