Limitations of Vision Screening Programs

• What are the limitations of vision screening programs?
• How is a comprehensive eye and vision examination different from a vision screening?

Vision screening programs are intended to identify children or adults who may have undetected vision problems. If the screening indicates a vision problem, they are referred for further evaluation.

However, a vision screening can't be relied on to provide the same results as a comprehensive eye and vision examination.

Screenings can take many forms. Often schools provide periodic vision screenings for their students. A pediatrician or other primary care physician may do a vision screening as part of a school physical. When applying for a driver's license, your vision will likely be screened. Vision screenings are often part of local health fairs put on by hospitals, social service agencies or fraternal groups like the Lions and Elks clubs.

Vision screenings can uncover some vision problems, but they can miss more than they find. This is a major concern about vision screening programs.

Current vision screening methods cannot be relied on to effectively identify individuals who need vision care. In some cases, vision screening may actually inhibit the early diagnosis of vision problems. Screenings can create a false sense of security for those individuals who "pass" the screening but who actually have a vision problem. These people are then less likely to receive treatment for their vision problem-and it could become worse.

Undetected and untreated vision problems can interfere with a child's ability to learn in school and participate in sports. They can also affect an adult's ability to do their job or to drive safely. The earlier a vision problem is diagnosed and treated, the less it will impact an individual's quality of life.

What are the limitations of vision screening programs?

To understand why vision screenings may not find a vision problem, let's look at the factors that can limit their effectiveness.

• Limited testing. Many vision screenings test only for distance visual acuity. While the ability to see clearly in the distance is important, it does not indicate how well the eyes focus up close or work together. It also does not give any information about the health of the eyes.
  
  Some screenings may also include a plus lens test for farsightedness and a test of eye coordination. However, even these additional screening tests will miss many vision problems.
  
  
• Untrained personnel. Often, administrative personnel or volunteers who have little training conduct a vision screening. While well-intentioned, these individuals do not have the knowledge to competently assess screening results.
  
  
• Inadequate testing equipment. Even when done in a pediatrician's or primary care physician's office, the scope of vision screening may be limited by the type of testing equipment available. Factors such as room lighting, testing distances and maintenance of the testing equipment can also affect test results.

People often misunderstand what passing a vision screening means. The information obtained from a vision screening is comparable to the information obtained from a blood pressure measurement. Your blood pressure may be in normal range, but that doesn't mean that you do not have other health problems. It's merely a single measure of one aspect of your overall health. Just like you need a complete physical to evaluate your total health, only a comprehensive eye and vision examination can evaluate your overall eye health and vision status.

[back to top]

How is a comprehensive eye and vision examination different from a vision screening?

A Specialized equipment and procedures, which are not available as part of a vision screening program, are needed to adequately evaluate your eyes and vision.

Only an optometrist or ophthalmologist can conduct a comprehensive eye and vision examination. These doctors have the specialized training necessary to make a definitive diagnosis and prescribe treatment.

A comprehensive adult eye and vision examination includes:

• Patient and family health history
• Visual acuity measurement
• Preliminary tests of visual function and eye health, including depth perception, color vision, peripheral (side) vision and response of the pupils to light
• Assessment of refractive status to determine the presence of nearsightedness, farsightedness or astigmatism
• Evaluation of eye focusing, eye teaming and eye movement abilities
• Eye health examination
• Additional tests as needed

Vision screening programs can't substitute for regular professional vision care. Children or adults who pass a vision screening could still have an eye health or vision problem. Professional examinations are the only effective way to confirm or rule out any eye disease or vision problem. The American Optometric Association recommends the following frequency of eye and vision examinations by age.

Frequency of Examination

[back to top]