Crossed eyes, also called strabismus, is a condition in which your eyes do not line up properly. If you have this condition, your eyes look in different directions, with each eye focusing on a different object. The disorder is very common in children, affecting four percent of children age 6 and younger. Its cause at birth is not known, but it does tend to run in families. In adults, the disorder can be caused by a variety of factors, including a brain tumor, retina damage, diabetes, or a stroke. Crossed eyes can usually be corrected with eyeglasses and/or surgery.
Types of Crossed Eyes
Two types of crossed eyes are common in children. One appears in infancy and the other develops as a child grows older.
Infantile Esotropia appears in babies during their first year of life. One eye may cross more often than the other. It typically runs in families and usually requires surgery to correct.
Acquired Esotropia occurs in children between the ages of 2 and 5 and can usually be corrected with eyeglasses.
What Causes Crossed Eyes?
Crossed eyes occur when the numerous muscles around the eyes do not work in conjunction because some are weaker than others. When the brain receives a different visual message from each eye, it ignores the one coming from the weaker eye. Over time, you may lose vision in your weaker eye if the condition is not corrected.
Crossed eyes can also occur later in life and are usually triggered by physical disorders such as a brain tumor or an eye injury. If you have a lazy eye or are farsighted, it is also possible to develop crossed eyes as an adult because your eyes must strain in order to focus on objects. People with brain or nervous system disorders such as cerebral palsy are more likely to have strabismus.
Who Is at Risk for Crossed Eyes?
You are at risk for strabismus if:
- your family members have the disorder
- you have a brain disorder or brain tumor
- your retina is damaged
- you have suffered a stroke or brain injury
- you are diabetic
- you have a lazy eye, are farsighted, or have vision loss
Symptoms and Signs of Crossed Eyes
Symptoms may be constant or appear only when you (or your child) are tired or not feeling well. Your eyes might point inward or outward or focus in different directions.
It is common for newborn babies to experience strabismus, but if it persists beyond 3 months of age, it is best to see a doctor. In addition to having crossed eyes, you might also:
- have impaired vision
- lose depth perception
- have double vision
How Are Crossed Eyes Diagnosed?
For a strabismus diagnosis, you will visit an eye doctor who will perform a series of tests to check the health of your eyes, including a:
- corneal light reflex test to check for crossed eyes
- visual acuity test to determine how well you can read from a distance
- cover/uncover test to measure deviation and eye movement
- retina exam to examine the back of your eyes
Early diagnosis is important for preventing vision loss. In young children, it is best to have an eye exam before age 3. If other physical symptoms appear along with crossed eyes, your doctor may examine your brain and nervous system for the presence of other conditions, such as cerebral palsy or Guillain-Barre syndrome.
How Are Crossed Eyes Treated?
Treatment for strabismus depends on its severity and cause. If you have developed a lazy eye, you might need to wear a patch over your stronger eye to force the muscles of your weaker eye to work harder. Other common treatments include:
- eyeglasses, particularly in the case of farsightedness
- surgery to strengthen certain eye muscles, particularly if glasses have not corrected the condition
- eye exercises
- eye drops to blur vision in the better eye
According to Dr. James McDonnell from Loyola University, adults do not always need to have surgery to correct this condition. Botox, commonly used in cosmetic procedures, can also be applied to weaken the stronger eye muscle, giving the weaker muscle a chance to gain strength.
In some cases, crossed eye symptoms may come and go, making it necessary to wear glasses and frequently do eye exercises to align your eyes. The condition sometimes occurs because of vision deterioration; in this case, you must have your vision loss corrected in order for strabismus surgery to be effective.
What Is the Long-Term Outlook for Crossed Eyes?
In many cases, crossed eyes can be corrected with treatment, though you may still have vision problems after surgery and need to wear glasses. Seek treatment for the problem right away because it can sometimes lead to vision loss. The condition may also recur, so it is important to monitor it regularly.