You may have heard of the phrase “lazy eye,” which is oftentimes used to describe when one eye has reduced vision. Eye care professionals refer to this condition as amblyopia. If it is not detected and treated early, amblyopia has the potential to permanently effect vision. In many cases of amblyopia, the affected child may not demonstrate symptoms of vision problems. This is why it is important for your child to be examined by an optometrist, even if you do not suspect problems.
What is Amblyopia?
Amblyopia occurs when the connection between the eye and the brain is not fully developed. In childhood, the brain is constantly learning and forming new connections. If one eye does not appropriately communicate with the brain, the brain will begin to ignore the input signal from the “bad” eye. If this is not fixed during the developmental period, it could result in permanently reduced vision in the “bad” eye which glasses or contact lenses cannot fix.
Causes of Amblyopia
There are several main causes for the development of amblyopia. The most common reason amblyopia develops is due to a strabismus, or an eye turn. In strabismic amblyopia, one of the eyes is turned inward or outward because of a misalignment of the muscles around the eye. This can lead to double vision and visual confusion, so the brain learns to ignore input from the misaligned eye. When the brain continues to ignore this eye, the proper signals are not developed and the eye can experience reduced vision. Refractive amblyopia is another form, which is caused when there is a dramatic difference in prescription between the two eyes. If one of the eyes has a more significant prescription than the other eye, that eye will see much worse without the help of glasses or contact lenses. During childhood, when important eye-brain connections are being made, the brain will simply begin to ignore the eye that is inputting a blurry image. The final cause of a lazy eye is called deprivation amblyopia. This can happen when something is physically blocking the signal from one eye from reaching the brain, such as a dense cataract or a malfunctioning eyelid.
Risk Factors for Lazy Eye
Many children with risk factors for amblyopia do not demonstrate symptoms. Because they usually have good vision out of one eye, they may not show symptoms of visual problems such as squinting, head tilting, or holding objects very close. For this reason, it is important that children are examined throughout the developmental period so their doctor can ensure their vision is developing properly. The American Optometric Association recommends evaluation at 6 months, 3 years, and 5-6 years of age. If your child’s optometrist suspects that your child is at risk for amblyopia, they will begin treatment to prevent permanently reduced vision, and the underlying cause of your child’s amblyopia will determine exactly how they are treated. If your child has refractive amblyopia, they will be prescribed a pair of glasses that should be worn full time. These help promote equally clear images being sent from the eyes to the brain. If your child has a strabismus, they will likely recommend eye patching, where the good eye is covered up and the brain is forced to use the misaligned eye. This can help promote proper muscle control and can strengthen the connection between the misaligned eye and the brain. Your doctor may have several other suggestions to help reduce the risk of permanent vision reduction for your child. The important part is to catch the condition early, so effective treatment can be put in place.