Vision Screenings vs. Eye Exams: Why Are Eye Exams Important?
Is it really that important to have routine eye exams? What if you just passed a vision screening at work or school — do you still need an eye exam?
Here are a few important differences between vision screenings and eye exams — and why routine eye exams are so important even if you've passed a vision screening.
Vision Screenings Are Not Eye Exams
Vision screenings are not comprehensive eye exams. Screenings usually take only a few minutes and are often performed by volunteers who are not eye care professionals.
In many cases, vision screenings are nothing more than a visual acuity test where you're asked to identify the smallest letters you can on a vision chart across the room.
After a comprehensive exam, your eye doctor will discuss the findings and offer treatment options best suited to your needs.
Vision screenings typically are designed to only detect subnormal visual acuity and major vision problems — as quickly and cost-effectively as possible. They generally are ineffective for detecting more subtle vision problems and potentially sight-robbing eye diseases.
People who fail a vision screening (usually because their visual acuity is worse than 20/40) are made aware of this and are encouraged to visit an eye doctor so they can have their vision problem professionally diagnosed and treated with eyeglasses, contact lenses, medicine or surgery.
Eye exams, on the other hand, are performed by licensed eye doctors (an optometrist or ophthalmologist) and evaluate not only your visual acuity, but also the complete health of your eyes, from front to back — including checking for early signs of serious eye problems such as glaucoma, cataracts, macular degeneration and detached retina.
Your eye doctor also can detect early signs of serious health problems such as diabetes, high blood pressure and risk of stroke, based on the appearance of delicate blood vessels and other structures within the eye.
Children's Vision Screenings Are Helpful — But Kids Need Eye Exams, Too
Good vision is essential for children to reach their full academic potential. It's been widely stated that roughly 80 percent of what children learn in school is presented visually, and vision problems can have a profound effect on learning.
According to the American Optometric Association, an estimated 20 percent of preschool children have vision problems. Other research shows that 24 percent of adolescents with correctable refractive errors (nearsightedness, farsightedness and/or astigmatism) don't have their vision fully corrected with up-to-date prescription eyeglasses or contact lenses.
Children's eye exams are important to ensure normal vision development.
Also, children are using computers and other digital devices much more extensively and start using these devices at a much younger age than children in the past. The illuminated screens of these modern devices tend to be more visually demanding than books and other printed text.
Increased use of digital devices by children has occurred simultaneously with another significant trend — an unprecedented increase in myopia among children in the U.S. and worldwide. These two trends have led many eye care professionals to believe computers and digital devices play an important role in the development of nearsightedness and myopia progression. This makes it more important than ever for children to have their eyes examined routinely to identify and treat vision problems.
Vision screenings are helpful to identify children who already have significant myopia, but screenings aren't sensitive or thorough enough to identify all children who have vision problems that can affect their learning.
Passing A Vision Screening Doesn't Mean Your Child's Vision Is Perfect
Even if your child passes a school vision screening, it doesn't guarantee he or she has perfect vision or has all the required visual skills needed for optimum performance in the classroom.
In fact, a number of studies have identified significant challenges and shortcomings of children's vision screenings, including:
- Children with significant learning-related vision problems being able to pass simple school vision screenings
- Poor consistency of screening results among different volunteers conducting the testing
- Parents being unaware their child failed a vision screening
- Lack of follow-up to make sure children who fail screening actually have an eye exam
Also, poor standardization of vision screening standards among different states and lack of reporting requirements make it impossible to adequately evaluate the effectiveness of school vision screenings.
Older Adults Need More Frequent Eye Exams
On the other end of the age spectrum, many older Americans often forgo routine eye exams and falsely believe that free vision screenings offer adequate monitoring and protection of their eyesight.
This is extremely dangerous, since the most common causes of blindness — glaucoma, diabetic retinopathy and macular degeneration — increase with age. Vision loss often can be prevented or reduced if these conditions are diagnosed and treated early. But the only way this can be done is to have routine comprehensive eye exams.
Don't take chances with your eyesight as you get older. It may be sufficient to have a comprehensive eye exam every two years in your early adult life. But if you're over age 60, have an annual eye exam to preserve your vision and make sure you are seeing the world as clearly as possible. [Read more about when to have an eye exam.]
Though Medicare does not cover routine eye exams, if you have a Medicare supplement policy or other medical or vision insurance, your benefits may include an annual comprehensive eye exam. Check with your insurance provider for details.
About the Author: Gary Heiting, OD, is senior editor of AllAboutVision.com. Dr. Heiting has more than 25 years of experience as an eye care provider, health educator and consultant to the eyewear industry. His special interests include contact lenses, nutrition and preventive vision care.
Page updated August 2017