What is amblyopia?
Amblyopia is a condition where one eye develops abnormally in early life. The weak, or 'lazy', eye often wanders inwards or outwards. In rare cases, both eyes can be affected. If left untreated, amblyopia can lead to permanent vision loss in the affected eye.
The condition usually occurs in children between birth and age 7 and is the leading cause of decreased vision in one eye in children. Amblyopia is more common in small or premature babies, or children with a family history of the condition.
What are the symptoms of amblyopia?
Signs that your child might have amblyopia include:
- eyes that don't seem to 'work together'
- an eye that wanders inwards or outwards
- squinting or shutting one eye
- head tilting
- poor depth perception
See a doctor if you notice your baby’s eye wandering in their alignment any time after the first few weeks following birth. It is also a good idea to have your child’s eyes tested before they start school.
What causes of amblyopia?
Amblyopia develops when one eye receives weaker visual signals in early life. Because the brain receives these fewer visual signals, it starts to ignore input from that eye and so the eyes do not work together properly.
Amblyopia can be caused by anything that blurs a child's vision or causes crossed eyes. Common causes include:
- an imbalance in the muscles that position the eyes (known as strabismus)
- a difference in the sharpness of vision between the eyes
- an imperfection on the surface of the eye (astigmatism)
- any problem with one eye, such as a cloudy area in the lens (cataract)
How is amblyopia diagnosed?
How is amblyopia treated?
The earlier treatment starts, the better the outcome. This is because it is important to correct amblyopia while the connections between the eyes and the brain are forming.
The type of treatment will depend on the cause of amblyopia and whether it is affecting your child's vision. Some options include:
- glasses or contact lenses to correct conditions such as near-sightedness, far-sightedness and astigmatism
- an eye patch over the stronger eye to stimulate the weaker eye
- a special filter to blur the vision of the stronger eye and stimulate the weaker eye
- eye drops to blur the vision of the stronger eye
- surgery if your child's eyes are wandering, or to correct cataracts or droopy eyelids
The treatment usually works within several weeks or months, although it can continue for up to 2 years.
Amblyopia can return in 25 per cent of cases (1 in 4 cases). It’s therefore important to continue to monitor your child’s eyes after the treatment stops.
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Last reviewed: October 2019