When the brain does not receive clear images from the eyes during early childhood, it learns to ignore the weaker eye, causing the condition of lazy eye, or amblyopia. A lazy eye can cause poor vision, poor depth perception, and eye strain.
Lazy eye can be caused by different factors that interfere with the normal development of vision in the eyes. Some common causes are:
A strabismus is a misalignment of the eyes, such as crossed eyes or wall eyes, which prevents the eyes from working together and causes the brain to favor one eye over the other.
The shape or size of the eye affects how it concentrates light, which is known as refractive errors. Nearsightedness, farsightedness, and astigmatism can cause blurred vision in one or both eyes, and the brain ignores the one with poorer vision.
Cataracts are cloudy areas in the lens of the eye that block or distort light. They can affect one or both eyes, and can cause dim or blurry vision. They can also prevent the brain from receiving clear signals from the eye.
A ptosis is a drooping of the upper eyelid that covers part or all of the eye. It can affect one eye or both, and reduces the amount of light entering the eye. It can also prevent the brain from receiving clear images from the eye.
Lazy eye may not have obvious signs or symptoms, especially if it affects only one eye. It may be detected during a routine eye exam or vision screening. Some possible symptoms are:
Blurred or dim vision in one or both eyes
Difficulty seeing in 3D or judging distances
Eye strain or headaches when reading or doing close work
Squinting, closing, or covering one eye to see better
An eye that wanders or drifts inward or outward
To diagnose lazy eye, an eye doctor will perform a comprehensive eye exam and ask about the medical history and symptoms. The eye exam may include:
Visual acuity test: This test measures how well each eye can see letters or shapes on a chart at different distances.
Cover test: This test checks how the eyes move and work together. The doctor covers one eye at a time and observes how the other eye moves or shifts.
Refraction test: This test determines the prescription for glasses or contact lenses. The doctor uses a device called a phoropter to place different lenses in front of the eyes and measure how they focus light.
Eye health exam: This exam evaluates the health and structure of the eyes. The doctor uses a device called an ophthalmoscope to look inside the eyes and check for any problems or abnormalities.
The treatment of lazy eye aims to improve the vision in the weaker eye and make the brain use both eyes equally. The treatment may include:
Corrective lenses: Corrective lenses are glasses or contact lenses that correct the refractive errors in the eyes. They help the eyes focus light better and send clearer images to the brain.
Eye patching: Eye patching is covering the stronger eye with a patch for several hours a day. It forces the brain to use the weaker eye and improve its vision.
Atropine drops: Atropine drops are eye drops that temporarily blur the vision in the stronger eye. They have a similar effect as eye patching, but may be more convenient or comfortable for some children.
Vision therapy: Vision therapy is a series of exercises and activities that train the eyes and the brain to work together. It helps improve the eye alignment, coordination, and focus.
Surgery: Surgery may be needed to treat the underlying causes of lazy eye, such as strabismus, cataracts, or ptosis. It can help improve the appearance and function of the eyes.
Lazy eye can be prevented or detected early by following these tips:
Children should have their first eye exam at 6 months of age, and then again at 3 and 5 years of age. After that, they should have an eye exam once a year or as recommended by their eye doctor.
Treat eye problems promptly: Any eye problems, such as infections, injuries, or allergies, should be treated as soon as possible to avoid complications or damage to the eyes.
To avoid complications or damage to the eyes, any eye problems, such as infections, injuries, or allergies, should be treated promptlyt their screen time to no more than 2 hours a day, and take breaks every 20 minutes.
