Eye Chart Exams May not Provide Clear Diagnosis in Teens

The National Eye Institute hailed May as Healthy Vision Month, encouraging people to be aware of their eye health and to schedule comprehensive eye exams. These exams include dilating the eye to check for damage on the retina, tonometry tests to detect glaucoma, and the ever familiar eye chart exam, long the standard test for visual acuity.

Each of these exams is valuable in diagnosing vision problems in people of varying ages. Except, perhaps, the eye chart.

How Eye Chart Exams Work

Developed by Dr. Hermann Snellen in 1862, the standard—or Snellen—eye chart tests how sharply patients see the rows of letters on the chart, which grow progressively smaller with each descending row. The smallest row patients are able to read corresponds with their visual acuity.

Eye doctors have relied on this test for years as a tool for detecting:

• Myopia (nearsightedness)
• Hyperopia (farsightedness)
• Astigmatism (distortions of the cornea or lens)

Although the test is simple and economical, there are increasing questions as to its viability in helping diagnose certain conditions in teens.

The Problem with Eye Charts and Teens

An intriguing Australian study found that eye chart exams are not good tools for detecting hyperopia and astigmatism in teenagers. The study examined approximately 2,400 teens and discovered that there was a reliable cut-off point for the number of letters a child could read that signaled myopia, but there was no reliable cut-off point that signaled hyperopia or astigmatism.

Children known to have these conditions were able to read up to 57 and 55 letters respectively, but these numbers correspond to a visual acuity score that falls within the normal range. This means that teenagers with astigmatism and hyperopia are passing eye chart exams and may not be getting the treatment they need.

In the spirit of Healthy Vision Month, take extra measures to ensure that everyone in your family is getting proper eye care. While eye chart exams seem to work to detect problems in adults, they may not accurately see problems in your children’s eyes, and it is well worth looking for extra tests to shed light on potential problems.

To find an ophthalmologist near you and to learn more about LASIK vision correction, contact The LASIK Directory today.