What Is the Most Common Cause of Strabismus?
Strabismus is a condition in which the eyes do not point in the same direction. One eye may turn inward, outward, upward, or downward while the other eye looks straight ahead.
There is no single cause responsible for every case of strabismus. In many children, the condition develops because the brain and eye muscles do not coordinate eye movement properly, even though the child is otherwise healthy. A common identifiable cause in children is uncorrected farsightedness, which can cause the eyes to cross inward while focusing.
How Does Farsightedness Cause Strabismus?
Farsightedness, also called hyperopia, requires the eyes to work harder to focus clearly. Focusing and inward eye movement are closely connected. When a farsighted child makes an extra focusing effort, one or both eyes may turn inward.
This type of strabismus is known as accommodative esotropia. It is a common form of childhood strabismus and frequently begins between ages 2 and 4, although it can develop earlier or later.
Properly prescribed glasses may help straighten the eyes by reducing the focusing effort. Some children may still have eye crossing while wearing glasses and require additional treatment.
Other Causes of Strabismus in Children
Childhood strabismus may also be associated with:
- A family history of strabismus
- Differences in vision or eyeglass prescription between the eyes
- Poor vision caused by cataracts, retinal disease, or optic nerve problems
- Premature birth
- Cerebral palsy
- Down syndrome
- Hydrocephalus
- Certain genetic or neurological conditions
- Injury to the eye or brain
However, many children with strabismus have no other medical condition and no clearly identifiable cause. The American Association for Pediatric Ophthalmology and Strabismus notes that strabismus frequently occurs in otherwise healthy children.
What Causes Strabismus in Adults?
Adults may have strabismus that has been present since childhood, even if it becomes more noticeable later. New strabismus in adulthood may result from:
- Cranial nerve palsy
- Stroke or another vascular condition
- Thyroid eye disease
- Head or eye trauma
- Myasthenia gravis
- Changes in the muscles and tissues surrounding the eyes
- Previous eye surgery
- Neurological conditions
- Tumors, although this is less common
Sudden eye misalignment in an adult commonly produces double vision and should be evaluated promptly. A new eye turn can occasionally indicate a serious underlying medical problem.
Is Strabismus Hereditary?
Strabismus can run in families, but its inheritance is not always straightforward. A child with a parent or sibling who has strabismus has a higher risk of developing eye misalignment. Family members may have different types or degrees of strabismus.
Children with a family history of strabismus should receive regular vision screenings and a comprehensive eye examination if signs of misalignment appear.
What Are the Signs of Strabismus?
Common signs include:
- One eye turning inward or outward
- Eyes that do not appear to work together
- Closing or covering one eye
- Squinting in bright light
- Tilting or turning the head to see
- Poor depth perception
- Double vision, especially in adults
- An eye turn that becomes more noticeable when tired or sick
An eye may turn constantly or only occasionally. Even an intermittent eye turn should be evaluated, particularly in a young child.
Can Strabismus Cause Lazy Eye?
Strabismus can lead to amblyopia, commonly called “lazy eye.” When a child’s eyes are misaligned, the brain may begin ignoring the image from the turned eye to prevent double vision. Over time, vision in that eye may not develop normally.
Early diagnosis is important because amblyopia is generally easier to treat while the visual system is still developing.
Strabismus Evaluation in Las Vegas
The most common identifiable causes of childhood strabismus include problems with eye coordination and farsightedness, but every patient is different. A comprehensive examination is necessary to identify the type of strabismus and recommend appropriate treatment.
The pediatric ophthalmology and strabismus specialists at Meadows Eye Physicians & Surgeons evaluate eye misalignment in children and adults. Contact our office to schedule a comprehensive strabismus evaluation.
Call Meadows Eye Physicians & Surgeons at (702) 358-0472.