Eye charts are a traditional part of eye exams for older children and adults, but for young children who may not know the entire alphabet yet, these lettered charts aren't used. When you take your child to the optometrist for their first eye exam, they'll undergo a lesser-known test: photoscreening. Here are three things parents need to know about photoscreening.
How is photoscreening performed?
Your child will be taken to a dark room for this test. These low light levels are important because they allow your child's pupils to dilate.
Once your child's pupils have dilated enough, the optometrist will hold a device called a photoscreener in front of their face. The optometrist will then take a series of flash photographs of the retina and other intraocular structures.
The results from photoscreening will be available very quickly since the photos are analyzed by software. It may only take seconds for the optometrist to receive the results from the test.
What problems can photoscreening detect?
Photoscreening can be used to detect refractive errors. Refractive errors include nearsightedness and farsightedness and occur when the eyes don't bend light properly. These errors can be corrected with glasses, and,when your child gets older, contact lenses. Catching refractive errors early is important because if your child starts school with poor vision, they may have trouble learning.
Amblyopia can also be detected through photoscreening. Amblyopia is the medical term for lazy eye, and it occurs when one eye has better vision than the other, allowing the weaker eye to become lazy. If the condition is caught early, it can be treated with eye patching, but if it's not detected, the lazy eye may become blind.
Undiagnosed vision problems are very common—one study reported that 14% of Kentucky kindergarteners had them—but with proper screening, your child can receive the treatment they need.
When are additional tests necessary?
If the test detects refractive errors, additional testing will be needed. This is because photoscreening can detect the error, but it can't detect the extent of the problem and allow the optometrist to create a prescription for glasses.
Refraction, an additional test, is used in these cases. During this test, your child will look at a chart through a refractor device. The optometrist will add different lenses to the refractor and will ask your child if the chart looks clearer or blurrier. Even if they don't know all of their letters yet, they'll still be able to tell which chart is clearer based on the letters they do know. Based on this information, their optometrist will know what prescription they need.
Untreated vision problems are common among young children, but with photoscreening, these problems can be caught early.
For further assistance, contact a local professional, such as Dr Gary Wetmore Optometry.