Strabismus is the condition when the eye muscles do not work together to keep both eyes looking in the same direction (binocular vision). One eye is either turned in, out, up or down. When the eyes are not aligned in adults, two images are seen. This results in double vision (diplopia). The most common form of strabismus happens in childhood while the brains ability to interpret visual impulses is still developing. In order to avoid double vision, the brain trains itself to ignore what direction one eye wants go. After a while, the brain will continue to suppress the vision in one eye (amblyopia). For this reason, if a turned eye is present, it is treated right away in young children. If treated at an early stage, amblyopia may not develop.


In children:

  • Passed down from parents (hereditary).

  • A result of far-sightedness.

In adults the sudden onset of strabismus may be caused by:

  • Diabetes.

  • Stroke.

  • Migraine headache.

  • Diseases of unknown causes (Bell's palsy or other weakness of the nerves that control the eye muscles).

  • Viral infection.

  • Tumors or abnormal blood vessels growing behind the eye.

  • Thyroid gland disease.

  • Brain tumor.

  • Traumatic brain injury.

  • Muscle relaxants or other drugs and medicines.

  • Guillian-Barre syndrome, Botulism, shellfish poisoning and other rare disorders.


  • Usually a parent will notice that one eye is turned in, out, up or down.

  • There may be sensitivity to bright light when one eye wanders toward a bright light source such as sunlight. The child may squint or keep the wandering eye closed.

  • Eyes turn in when reading or focusing on close objects. This results in headaches, eye tiredness (fatigue), and eye strain.

  • Adults may have poor depth perception since their eyes do not work together.

  • Seeing two of everything. This is almost always a symptom of another serious disorder, such as diabetes, a stroke, a tumor around the eyes, thyroid disease, or a brain tumor.


Trained eye professionals (optometrists and ophthalmologists) diagnose strabismus (eye muscle problems) with an examination in the office.


  • Children may have to wear an eye patch to stimulate vision equally in both eyes.

  • In adults, treatment depends on what is causing the strabismus. One eye may need to be patched to avoid double-vision.

  • Eye drops may be used to blur the vision in the better eye.

  • If glasses are needed, they will be prescribed even for very young children (as young as one year of age).

  • Surgery may be needed on the muscles to align the eyes. This is usually done under general anesthesia as early in life as possible after one year of age. The earlier the eyes become aligned, the less likelihood that amblyopia will develop.

  • Many cases of strabismus in children do not need surgery but can be treated with a combination of patching and special eye exercises (orthotics). Your eye specialist may refer you to a professional with expertise in eye muscle exercises (orthoptist) as a part of the treatment of amblyopia.

  • In milder cases, special glasses can be made with prisms in the lenses to help bring together the separate images coming from each eye into one image.

  • The longer one waits to treat amblyopia, the less chance there is of restoring vision to the affected eye. Amblyopia is generally not treatable after the age of 10.


  • You notice that the eyes of a child or infant do not appear to be looking in the same direction.

  • A child does not seem to see as well with one eye as with the other.

  • There is a sudden development of poor depth perception in an adult.

  • You see two of everything when looking straight ahead or in one particular direction.