Amblyopia, commonly known as lazy eye, is a condition that typically affects children, and it causes signals from one eye to be ignored in favor of the other. Symptoms of amblyopia in children include a misalignment of the eyes, poor depth perception and squinting or turning the head when focusing on an object. The child might become distressed when one eye is covered. Other observed conditions, such as a cataract or drooping eyelid, might also partially block vision in one eye and could indicate amblyopia in children.
In normal vision, signals from both eyes are compiled by the brain to create a three-dimensional image. For children who have amblyopia, the images coming from the eyes are too dissimilar to blend into a single picture. The brain overcomes this confusion by ignoring one of the signals. Children who have amblyopia rely on one eye over the other, resulting in diminished or absent depth perception.
Lack of depth perception is one of the primary symptoms of amblyopia in children. Other common symptoms include a tendency to squint or tilt the head when attempting to focus on an object. Small children who have amblyopia might cry or become distressed if the stronger eye is covered.
Most often, amblyopia in children is a result of strabismus, or a misalignment of the eyes. The child’s eyes appear to look in different directions, making this condition easily diagnosed. Strabismic amblyopia might be observed at birth, or the condition might develop later.
When the ability to focus on an object is mismatched, such as when only one eye is nearsighted, amblyopia can result. As with the misalignment, the pictures transmitted from the eyes do not match, leading the brain to ignore the signals from the weaker eye. This form of amblyopia, called refractive amblyopia, is more difficult to spot. The eyes are not likely to appear misaligned, but other symptoms might be observed, such as poor depth perception and difficulties focusing.
Physical obstacles might also block the vision in one eye, resulting in amblyopia in children. Cataracts form an opaque cloud inside the eye, and it blurs vision, resulting in mismatched images being sent to the brain. These cause the pupils to appear pale and cloudy and are easily observed indications that the child might suffer from amblyopia.
Ptosis, or a drooping eyelid, makes it difficult to open the eye fully, partially blocking vision. The brain ignores the poor-quality images from the hooded eye, resulting in amblyopia. Evidence of ptosis is a sign of potential amblyopia in children.