The main reason for vision screening in young children is to detect serious eye disease such as cataracts, retinoblastoma, glaucoma, etc. and to identify children at risk of developing amblyopia. What is amblyopia? The term amblyopia comes from the Greek words “amblys” meaning dull, faint or dimmed and “opt” meaning eyes, referring to vision or sight. Simply explained, amblyopia is when vision in one or both eyes is decreased due to abnormal development of vision during infancy or childhood. This problem can lead to permanent blindness.
Your brain and eyes work together to produce vision. Sometimes, during early development, the vision of one eye is decreased because it fails to work with the brain as it should. The brain will start to favor the eye with the stronger vision. It will ignore the images from the weaker eye. The eye with poor vision then becomes relaxed and begins to weaken. The brain centers for vision in the affected eye won’t develop normally leading to permanent vision loss if untreated. You will often hear amblyopia referred to as “lazy eye”, although oftentimes the eye will appear to be normal.
There are many reasons for impaired vision in children. The most common cause is refractive error, commonly referred to as nearsighted, farsighted, or an astigmatism (distorted or blurry vision due to an imperfection in the curvature of the eye). A child may have a refractive error that is worse in one eye. If not detected early, vision will not develop correctly. It may be hard to tell that your child has a vision problem since his vision seems fine while using both eyes together.
Occasionally, the eyes will point in different directions. You may find that one eye looks straight ahead while the other eye is turned up, down, in, or out. The medical term for this is strabismus. As you can imagine, a child with this condition will see double. The brain tries not to let this happen, so it may ignore the image from the eye that isn’t focused straight ahead, again making the eye weak. Physicians refer to this as strabismic amblyopia.
Some children are born with cataracts, where the lens of the eye is cloudy. This can also contribute to the development of amblyopia. It is similar in that one eye will have a blurred view and the other eye a clear view, so the child will favor the eye seeing clearly. This is called deprivation amblyopia.
Amblyopia is the most common cause of visual impairment in children. It affects between 2 to 3 out of every 100 children, but it is a highly preventable and treatable if recognized early. Unfortunately, it is also the most common cause of visual impairment in one eye among young and middle-aged adults.
So now that you understand what it is and how common it is, you may be wondering what you can do about it. The most important thing is see you pediatrician regularly for preventative exams or “well visits”. These visits are designed to look at the overall development of each child, screen for any problems, and treat as early as possible. Vision screenings are done at each well visit starting at 6 months and a visual acuity test (testing the vision in each eye individually) usually starting at age 3 and every year thereafter. If your pediatrician detects abnormal vision, they may refer you to a pediatric ophthalmologist for further testing and treatment.
There are different treatment options depending on the age of the patient or which type of amblyopia the child has. The goal of treatment is to force the child to use the eye with the weaker vision, thus strengthening it. Treatment methods include patching, eye drops or surgery.
Patching is a method of treatment that involves placing an adhesive patch over the stronger eye for a prescribed amount of time per day. Younger children may not do well with patching. Another method is using drops that temporarily blur the good eye. This treatment isn’t recommended for severe amblyopia. Both treatments can take weeks or months to see improvement. Some amblyopia improves with special glasses.
As parents, we want the best for our children and we try to do everything to protect them; we apply sunblock so they don’t get sunburned, we hold their hands while crossing the street, we make them wear a helmet while riding a bike, and immunize them against diseases. Why would we not protect their sight? If screenings are ignored and poor vision is not corrected, your child’s vision is at risk. Just remember that the earlier vision problems are found, the earlier treatment can take place which increases the likelihood that treatment will be successful. Loss of vision can affect your child her entire life. Your child’s vision is one of her most important assets – doesn’t it make sense to protect it?
Canyon View Pediatrics
AAPOS, American Association for Pediatric Ophthalmology and Strabismus https://aapos.org/terms/conditions/21
AAP (American Academy of Pediatrics, “Instrument-based Pediatric Vision Screening Policy Statement” Volume 130, Number 5 November 2012
Children’s Eye Foundation, “What Every Parent Needs to Know: A Simple Screening Can Save Sight”