After taking your child for a pediatric refraction eye exam, you'll want to fully understand the results and what they mean for your child's vision.
You may have initially scheduled the exam because your child was squinting, complaining about headaches or maybe mentioning that schoolwork on the board was difficult to follow. Or your pediatrician may have suggested that further testing was needed after a routine vision screening. Once the results are in, understanding them will help you know how to address these issues.
The eye doctor will, of course, walk you through the results of your child's vision screening. Still, it can be good to have your own baseline understanding so you can feel confident your child's vision care is moving in the right direction. Here's an overview of what you should know about a pediatric refraction eye exam.
As part of a comprehensive eye exam, people are routinely given refraction tests. These tests evaluate how clearly a patient can see by measuring how much light hits their retina—the nerve layer at the back of the eye. The test results can help determine if a patient needs an eyeglasses prescription or other type of vision correction.
There are a few different types of refraction tests, and your child's eye doctor will choose one or more of the following:
A computerized test that uses a machine to determine how much light is moving through your child's eyes.
A manual light reflex test where the doctor shines light into each eye and measures how much light is reflected by the retina.
A phoropter test¹, in which your child's face is positioned against a mask-like device called a phoropter. They will be asked to look through the device at an eye chart 20 feet away and identify the pictures or letters on it if they are able. The idea is to find the smallest row of items that the child can see.
Dilatation is commonly used in these tests because children tend to focus in on nearby visuals when they are supposed to be looking far away during examination. Optometrists will often perform a cycloplegic refraction, temporally relaxing the focus muscles in the eye with eye drops. This allows the eye doctor to measure farsightedness and get a true measure of refractive errors.
Eye exams are just as important for young children as going to the doctor for a physical. Ideally, children have their first eye exam at six months. School young children three years of age and around five or six years of age should also be checked by an eye doctor. School aged kids should have scheduled eye exams at least every other year.
If you're told that your child has 20/20 acuity, this means there is no refractive error to correct. When looking at your child's chart, you will see a zero, which means that there is no issue with their vision.
It is not uncommon for your child may have some type of refractive error². This means that light passing through the eye is not hitting the retina in quite the right spot. The most common refractive errors include:
Myopia (nearsightedness), which involves difficulty clearly seeing things in the distance, such as the board in the classroom. With nearsightedness, light is focused in front of the retina instead of directly on it.
Hyperopia (farsightedness), which means objects that are closer tend to be out of focus. In this case, light is focused behind the retina. Keep in mind that some children can have slight hyperopia early on that resolves on its own by adolescence.
Astigmatism, which causes blurred vision and difficulty seeing both up close and far away. This happens when the cornea is an unusual shape. Instead of being shaped like a sphere, it may be egg-shaped. Instead of focusing light to just one point, the unusually shaped cornea may refract it to several points. Your child may be born with astigmatism or it may develop later from an injury or eye disease. Keep in mind, your child can have astigmatism along with either myopia or hyperopia.
Depending on the extent of any errors in refraction, your child may be prescribed glasses. On the chart, myopia will be noted with a minus sign next to a number while hyperopia will be recorded with a plus sign. The higher the number, the greater the refractive error and the stronger the prescription.
An astigmatism will be noted as a cylinder, which represents the amount of astigmatism present. The axis of the cylinder will show where the astigmatism is located.
You will also likely see these abbreviations if you look at your child's chart:
OD: Means right eye
OS: Means left eye
OU: Means both eyes
While each eye will be evaluated separately, how the vision functions in both eyes is also important. If the doctor finds a big difference between the vision of the two eyes, this is known as anisometropia³. In cases where this difference is significant, your child will likely be referred for amblyopia⁴ treatment.
Amblyopia is more commonly known as "lazy eye," and can result from significant vision differences between the two eyes. It can also be caused by conditions such as muscle misalignment, cataracts in the eye's lens, and even drooping eyelids.
If amblyopia is not corrected, the weaker eye won't develop properly and can lead to permanent vision loss. However, early treatment can prevent this from occurring. Treatment may include the following:
Patching the stronger eye for several weeks to months so the other has a chance to develop.
Putting eye drops in the stronger eye to blur the vision there.
Putting a lens in eyeglasses that blurs vision in the stronger eye.
Whatever the results of their initial pediatric refraction eye exam, children will need to have their refraction frequently tested. Expect to bring your child back every year or so for an eye exam if they need glasses.