Also known as “lazy eye,” amblyopia (am-blee-O-pea) occurs when vision in one eye (or both eyes) is impaired because the eye and brain are not working together. Often the eye itself looks normal, but it’s not being used normally because the brain is favoring the other eye. In children, amblyopia is the most common cause of visual impairment. Two to three out of every hundred children suffer from amblyopia. If left untreated, the condition will continue into adulthood and lead to visual impairment. The effects of this condition can range from mild to severe.
There are three types of amblyopia:
- Amblyopia secondary to misaligned eyes. In this situation, one eye is turned in or out. In order to prevent double vision, the brain suppresses or turns off the central vision from the eye that is not looking straight ahead. As the misaligned eye is turned off, pathways between the optic nerve and the brain are no longer forming leading to reduced vision.
- Refractive amblyopia: A big difference in prescription between the two eyes may result in this type of amblyopia. The dominant eye is typically the one that provides the brain with the clearest image. When the image from the other eye is blurry, it results in an abnormal development of one half of the visual system. Again, pathways between the retina and the brain aren’t stimulated to develop.
- Occlusion amblyopia: This type of amblyopia is seen in people with eye problems such as cataracts or tumors. Cataracts prevent normal visual input from reaching the eye, which results in disrupted development. In this form, if it is not treated during the early stages, amblyopia can persist after the cause of the opacity is removed.
Symptoms of severe amblyopia may include:
- Poor depth perception
- Eyes that turn in or out
- Eyes that obviously do not work together
- Low sensitivity to contrast
- Low sensitivity to motion
If you suspect amblyopia in yourself, your child, or someone you know, contact your eye doctor or healthcare provider to set an appointment.
Treating amblyopia typically involves treating the cause of the condition first.
- If cataracts are present the cataracts will be treated.
- If eyeglasses are needed for farsightedness or astigmatism, they are prescribed.
- It is common for an eye patch to be placed over the normal eye to force the brain to communicate and form pathways with the weaker eye.
- Occasionally, instead of an eye patch, eye drops are used to blur the vision of the dominant eye. The eye drops used to blur the good eye are called Atropine, and they are quite safe for monitored chronic use. Children will often refuse patching or Atropine treatment, but the parent must insist and take charge so that vision and normal depth perception can be restored.