Amblyopia, colloquially called lazy eye, impacts the vision of some young children, rendering one eye weaker than the other. The brain ignores the weaker eye in favor of the stronger eye, which is forced to compensate. Left untreated, amblyopia can lead to permanent vision loss in the lazy eye and may even cause total blindness. The condition affects two to three percent of the population.
To see better, a child with a lazy eye might shut one eye or squint. In some children, one eye wanders, or the eyes appear to gaze in opposite directions. Amblyopia can make it difficult to judge distances. Some children begin tilting their heads to see better. These symptoms often go unnoticed, which is why vision screening and examinations are essential for young children.
Strabismus makes the eyes unable to align when looking at the same object. The straighter eye tends to become the dominant eye, maintaining a healthy connection to the brain, but this leaves the weaker eye unable to focus, wandering in, out, down, or up. Eventually, the eye that works properly takes over the work of both eyes. Various visual differences in a child’s eyes can contribute to amblyopia. Both eyes may be nearsighted, farsighted, or a combination of both, causing uneven focus. Eyelids that droop can cause amblyopia by blocking vision. A cataract can lead to amblyopia due to blurry vision in the affected eye.
Low birth weight babies and those born prematurely have an increased risk of amblyopia. Children with developmental disabilities tend to be at higher risk. Genetics may also play a role in the development of amblyopia. Children at risk for the condition could develop progressively worse sight if they do not receive early vision screenings.
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When it is left untreated, amblyopia can lead to irreversible vision issues that affect several aspects of a child’s life. After age seven, it is less likely that treatment will provide the desired improvement. A child who does not see well may experience difficulty in school, face safety risks, or be unable to participate in sports due to impaired depth perception.
A child should see an eye doctor for vision screening as early as possible. A pediatrician can conduct an initial screening that may identify risk factors for amblyopia and other conditions. If the doctor diagnoses or suspects the condition, the child should be referred to a pediatric ophthalmologist for the most focused treatment.
An eye doctor uses various vision screening methods to test for eye conditions, including the red reflex test and the eye chart. The former is typically administered to infants. When the child gazes at the light from an ophthalmoscope, the pediatrician evaluates both eyes for red reflection. No reflection, less reflection in one eye, or bright red reflection in one eye could be evidence of amblyopia. In preschoolers, visual acuity — clarity or sharpness — may be evaluated using an eye chart.
The exam is administered by an ophthalmologist who evaluates a child’s eyes using special techniques and equipment. By dilating the child’s pupils using eye drops, the clinician obtains a better look at the eyes. As part of the examination, the ophthalmologist will gather a family history and note any concerns caregivers may have about their child's vision.
Glasses can correct amblyopia in some children. Wearing an eye patch over the healthy eye for a few weeks, up to a year, is another option; the patch forces the lazy eye to work. Eye doctors may also prescribe atropine eye drops: placing eye drops in the stronger eye causes blurred vision, which makes the weaker eye work.
Surgery may be necessary for a child whose amblyopia is associated with droopy eyelids, cataracts, or strabismus. Surgery to correct droopy eyelids prevents them from obstructing vision and other procedures can replace a lens damaged by cataracts. Surgery on the muscles of the eye can correct strabismus. After a surgical procedure, a child may be prescribed glasses to maintain the correction.
When young children receive appropriate treatment for amblyopia, the outcome is usually positive. The younger a child is when diagnosed and treated, the better the results. Early treatment can help children develop visual acuity and depth perception. Waiting until children are six or older makes it difficult, if not impossible, to improve their eyesight.
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