Amblyopia (Lazy Eye)

Medically Reviewed on 5/2/2023

What is a lazy eye (amblyopia)?

Amblyopia or lazy eye is the leading cause of vision loss in children.
Amblyopia or lazy eye is the leading cause of vision loss in children.

Amblyopia, often called lazy eye, is a vision-related condition that develops during infancy and early childhood. With amblyopia, an eye does not acquire normal visual acuity even while using prescription eyeglasses or contact lenses. Mostly, lazy eye occurs in just one eye. However, in certain circumstances, both eyes may have decreased visual acuity.

Early diagnosis in childhood and appropriate treatment can avert reduced vision due to amblyopia. If left untreated, a lazy eye can result in serious visual impairment in the affected eye.

What are the potential causes of amblyopia?

Amblyopia is the most common cause of visual loss in children and adolescents in developed nations, affecting three to four percent of school-aged children. In many cases, doctors are unable to determine the etiology of amblyopia.

Normally, the brain perceives using nerve impulses from both eyes. However, if a problem impairs vision in one eye, the brain may try to compensate. It begins to switch off signals from the weaker eye and may rely only on the stronger eye.

5 common causes of amblyopia

  1. Refractive errors: Are corrected with glasses or contacts. If they are not treated, the brain may begin to rely more on the stronger eye.
  2. Strabismus (crossed eye):
    • The eyes do not align.
    • One or both eyes are misaligned. To avoid seeing two images, the brain will cancel the vision of the deviated eye, preventing normal development of vision.
  3. Anisometropia:
    • Difference diopters (or size) of the eyes.
    • When one of the two eyes has a higher prescription than the other, the image gets blurrier. The brain will pick signals from the eye with a lower prescription and superior vision, and the other eye does not have to function.
  4. Cataract: Causes cloudiness in the lens of the eye and objects to appear blurry. Though most cataracts occur in elderly adults, newborns, and children can get a cataract.
  5. Not using glasses: Having prescription glasses but not using them may contribute to the development of a lazy eye. One of the most common causes of amblyopia is not wearing glasses, which might go undiagnosed.

A few other possible causes of amblyopia include:

  • Obstacles in the visual axis
  • The opacity of the cornea
  • Ptosis (droopy eyelid)
  • Retina diseases that interfere with the correct projection of the image to the brain
  • Trauma
  • Scarring
  • Vitamin A deficiency
  • Glaucoma

What are the risk factors of amblyopia?

Amblyopia risk factors include the following:

  • Premature birth
  • Small size at birth
  • Genetics or a family history of the condition
  • Developmental disabilities
  • Major differences in spectacle power between the two eyes

Is amblyopia brain damage?

The etiology of amblyopia is linked to developmental disorders and brain abnormalities. It occurs as a result of malfunctioning neural pathways in the brain that process vision. When both eyes are not used equally, this disorder or malfunction arises.

What are the signs and symptoms of amblyopia?

The main symptom of amblyopia is blurred vision. Infants and children are ignorant of the situation and do not complain. Even if amblyopia is present, the eye might appear entirely normal.

Common signs and symptoms of amblyopia include:

  • The baby cries or fusses when one eye is covered
  • Shutting one eye
  • Head tilting
  • Moving closer to objects
  • Bumping into things frequently (poor depth perception)
  • Misaligned eyes
  • Double vision or poor generalized vision
  • Difficulty catching and throwing objects
  • Not paying attention
  • Poor eye-hand coordination
  • Tripping and/or accident prone
  • The trouble with micro-eye movement
  • Slower reading speed and comprehension
  • Droopy eyelid
  • Eye strain
  • Headaches

Because amblyopia is usually due to a problem with infant vision development, the symptoms of the condition can be difficult to identify. If your child fusses or struggles when you cover one of their eyes, this could be an indication of amblyopia. Schedule an appointment with a local eye doctor to examine your child's eyes and ensure their eye health.


Pink Eye (Conjunctivitis) Symptoms, Causes, Treatments See Slideshow

How is amblyopia diagnosed?

Amblyopia can be difficult to diagnose without an eye exam.

Tests to diagnose amblyopia include the following:

  • Visual acuity: Tests vision. The person reads letters from an eye chart. Very young children could be examined using images.
  • Motility exam: A doctor checks the eyes to determine their correct alignment and identify any muscular dysfunction.
  • Refraction: The doctor will position a series of corrective lenses in front of the eyes to determine the right lens power required to compensate for a refractive error (nearsightedness, farsightedness, or astigmatism).

How do you fix a lazy eye (amblyopia)?

Amblyopia must be treated immediately because it will not resolve without treatment. Depending on the underlying cause, the doctor may recommend treatment options.

  • Vision therapy
    • Eye exercises in vision treatment encourage the eyes to operate together. The exercises in amblyopia require the brain to recognize the damaged eye, which restores vision in that eye.
    • Some physicians apply a patch to the more functioning eye, causing the less functional eye to work harder and develop stronger. The child must wear the patch only a few hours per day.
    • Treatment might span weeks or months depending on the severity of the problem. When a child refuses to wear a patch, a prosthetic contact lens is available. These contact lenses resemble the normal eye and are intended to obstruct vision in that eye.
  • Atropine drops
    • Some doctors treat amblyopia with atropine eye drops. These drops cause the child's superior eye to blur, encouraging the weaker eye to work harder and get stronger.
  • Prescription eyeglasses
    • If your child has amblyopia as a result of uncorrected vision, they require a pair of glasses. Amblyopia can occur when there is a strong uncorrected prescription or a significant difference in prescription between the two eyes. In addition to corrective glasses, your eye doctor may advise you to use eye patch therapy.
  • Surgery
    • Strabismus surgery is frequently necessary if the amblyopia is caused by a considerable eye turn.
    • Aligns the eyes and corrects the eye muscles. The eyes will be able to concentrate better after surgery.
    • Additional vision therapy could be necessary following strabismus surgery.

What is the outlook for a child with a lazy eye?

A lazy eye is treatable, and treatment can lead to better vision. Treatment could be required throughout childhood, and regular follow-ups are crucial. The time between follow-up appointments might range from a few weeks to months depending on the child's age, symptoms, and severity of the condition.

When is it too late to treat lazy eye?

Untreated amblyopia can result in persistent vision loss and decreased depth perception in the affected eye. When amblyopia is identified and treated before the child is nine years old, the weaker eye frequently improves dramatically. The most essential period to treat amblyopia is between three and six years.

How can I prevent lazy eye or amblyopia?

Amblyopia can be prevented by early detection and treatment of astigmatism, cataracts, strabismus, and other vision problems.

If you or your child has a family history of lazy eye and you fall under the risk group of amblyopia, talk to your doctor about ways to prevent lazy eye.

Tips to prevent lazy eye include the following:

  • Routine eye examination: The most essential thing parents can do to avoid lazy eyes is to get regular eye exams. Children may not recognize the signs of lazy eye and parents should step in to take their children to routine eye examinations.
  • Wear prescribed vision glasses: If a child is younger than seven years and requires glasses, the child must be encouraged to wear the prescribed vision glasses to develop optimal eyesight. Once the vision develops and the child is eight years old, the vision is permanent and will not alter.
  • Get operated for cataract: When the child's amblyopia is caused by a cataract and the doctor advises surgery to remove it.
Medically Reviewed on 5/2/2023
Image source: iStock Images

Amblyopia (Lazy Eye).

Amblyopia: What Is Lazy Eye?

Amblyopia. Amblyopia or “lazy eye.”