Eye health resource
Things You Need to Know About Strabismus
Strabismus means the eyes are not aligned in the same direction. Learn common types, how it can affect children and adults, how amblyopia relates to it, and why treatment depends on the cause.
Reviewed for accuracy by Justin Bazan, OD on .
Strabismus means the eyes are not aligned in the same direction. One eye may turn inward, outward, upward, or downward while the other eye points at the target.
Strabismus can begin in childhood or develop later in life. The cause, pattern, age of onset, and whether double vision is present all affect what evaluation and treatment are appropriate.
What Are the Main Types of Strabismus?
- Esotropia: one eye turns inward.
- Exotropia: one eye turns outward.
- Hypertropia: one eye sits higher than the other.
- Hypotropia: one eye sits lower than the other.
The misalignment may be constant or intermittent, and the same eye may not always be the one that turns.
Why Does Strabismus Matter in Children?
When a young child's eyes point in different directions, the brain may begin suppressing the image from one eye to avoid confusion or double vision. That can interfere with normal visual development and contribute to amblyopia, sometimes called “lazy eye.”
Strabismus and amblyopia are related but are not the same condition. Strabismus is an alignment problem. Amblyopia is reduced vision caused by abnormal visual development.
What Causes Strabismus?
There is no single cause. Some children have strabismus despite otherwise normal health. It can also be associated with significant refractive error, neurologic or developmental conditions, certain syndromes, or structural eye problems.
Adults may have strabismus that has been present since childhood or may develop new eye misalignment after a cranial-nerve problem, thyroid eye disease, stroke, head injury, eye surgery, myasthenia gravis, or another neurologic or orbital condition.
When Is New Strabismus More Urgent?
Sudden new eye misalignment or double vision in an adult deserves prompt medical evaluation. New diplopia can sometimes be the first sign of a neurologic, vascular, thyroid-related, or other medical problem.
In children, a new constant eye turn, an abnormal pupil, drooping eyelid, unusual eye movement, or other concerning neurologic or visual symptom should also be evaluated rather than waiting for a routine visit.
Can Glasses Treat Strabismus?
Sometimes. Certain forms of esotropia are driven partly by focusing effort related to farsightedness, and the right eyeglass prescription can significantly improve alignment. Other forms of strabismus are not corrected by ordinary glasses.
Prism can sometimes reduce double vision in selected patients by changing the direction light enters the eyes, but prism does not physically strengthen an eye muscle or permanently realign every type of strabismus.
What About Patching or Atropine?
Patching or atropine may be used to treat amblyopia when one eye has developed weaker vision. These treatments encourage use of the weaker eye.
They should not be described as treatments that mechanically straighten the eyes. Strabismus alignment and associated amblyopia may need to be managed as separate parts of the same child's care.
Can Eye Exercises or Vision Therapy Treat Strabismus?
Treatment depends on the type of strabismus. Selected eye exercises can be useful for particular binocular-vision conditions, while many forms of strabismus are treated with glasses, prism, amblyopia therapy, or eye-muscle surgery.
Park Slope Eye does not currently provide Vision Therapy. If an examination identifies a condition that would benefit from specialist strabismus or binocular-vision care, we can explain the finding and discuss referral options.
When Is Surgery Used?
Eye-muscle surgery can improve alignment when the type and amount of strabismus make surgery appropriate. Surgery is performed by an ophthalmologist with relevant expertise, not at Park Slope Eye.
Some patients still need glasses, prism, amblyopia treatment, or follow-up after surgery depending on the underlying condition.
Strabismus Evaluation at Park Slope Eye
A comprehensive eye exam can assess visual acuity, refractive error, eye alignment, eye movements, binocular function, and eye health. For children, see our pediatric eye care page. For medically driven symptoms or adult-onset eye misalignment, see medical eye care.
If you are concerned about an eye turn or double vision, book an appointment so the pattern can be evaluated and the appropriate next step determined.
Originally published . Substantially updated .