Vision Screenings vs Eye Exams

Schedule your child's comprehensive eye exam with our residency trained pediatric optometrist today at Artisan Optics in Boise Idaho


Vision screenings, we have all had them and if we pass a vision screening it is great because it means our eyes are doing well and we don't need an eye exam. Right? Guess again. While vision screenings are intended to catch people who need comprehensive examinations, it has been found that they can actually miss 25% - 60% of eye conditions!  


Don't have your child's eye condition missed and schedule an eye exam today at Artisan Optics in Boise Idaho


If you're thinking that number seems high, it is (we would hope for a much higher rate of identifying vision problems). Also think about this: if a person passes a screening who has a vision condition they are less likely to seek care. This means that the condition goes on another year (at least) before it is diagnosed and treated. Depending on the condition this could be sight threatening.


Vision screenings are not just done on children, they are also done with adults. Think about the last time you renewed your driver's license and they tested your visual acuity to determine if you were safe to drive. That is considered a vision screening. There is not a standardized protocol for screenings, which is why you get the varying levels of success in identifying vision conditions. Each organization or medical office has their own protocol in place.


There are efforts to make vision screenings more sensitive in determining if a comprehensive examination is indicated. An ophthalmic equipment company has developed a more accurate hand-held auto-refractor that is designed to detect refractive errors (prescription) as well as any ocular misalignment (strabismus). The company has also programmed the equipment to indicate if a referral is necessary based on a pre-set protocol. Technology is obviously making steps in the right direction, but everyone knows that technology is imperfect. This technology may have a hard time detecting intermittent ocular misalignments (check out our esotropia and exotropia blog) as well as have a difficult time assessing a refractive error if an individual has binocular difficulties such as an accommodative dysfunction. Obviously this is not a fault of the measurement but eye performance can be variable and difficult to determine in a snapshot of time. Also, a piece of equipment is only capable of identifying the conditions it was designed to detect. In other words, you will always miss the conditions you do not test for. This is why a comprehensive eye examination remains the gold standard for identifying vision conditions.


Variability can also play an important role in the results received during a vision screening. Is the person a trained professional or are they a volunteer? Is the patient apprehensive? Is the patient trying their best and do they understand what they are supposed to do? Is the testing environment optimal for testing? Even small differences can make a difference when it comes to an appropriate referral. Any referral from a vision screening is considered a good referral even if it is found that patient doesn't need glasses. A comprehensive examination will set up a baseline for that person's ocular health and refractive status.


When thinking about a pediatric vision screening it can be intimidating to screen young children because again...variability. Some children can't wait to try, while others are having a melt down and require coaxing. Generally pediatric vision screenings are minimal. They may include a visual acuity (if a child is able to perform this test) and an auto-refractor. Environment can also play a major role during pediatric testing. If they are in a crowded environment with their friends or in a busy medical office it may be out of their comfort zone or they just want to play. For children it is recommended they have a comprehensive examination with a residency trained pediatric eye care provider.


Pediatric Learning Related Eye Examinations are performed by a Pediatric Optometrist and include the following:

  • Acuity: Distance Vision: visual acuity (sharpness, clearness) at 20 foot distance.

  • Acuity: Near Vision: visual acuity for short distance (specifically, reading distance).

  • Focusing Skills: the ability of the eyes to maintain clear vision at varying distances.

  • Eye Tracking and Fixation Skills: the ability of the eyes to look at and accurately follow an object; this includes the ability to move the eyes across a sheet of paper while reading.

  • Binocular Vision or Fusion: the ability to use both eyes together at the same time.

  • Stereopis: binocular (two-eyed) depth perception.

  • Convergence and Eye Teaming Skills: the ability of the eyes to aim, move and work as a coordinated team.

  • Color Vision: the ability to differentiate colors.

  • Reversal Frequency: confusing letters or words(b,d; p,q; saw, was; etc).

  • Evaluation of age-appropriate vision skills.

  • Visual Memory: the ability to store and retrieve visual information.

  • Visual Form Discrimination: the ability to determine if two shapes, colors, sizes, position, or distances are the same or different.

  • Visual Motor Integration: the ability to combine visual input with other sensory input (hand and body movements, balance, hearing, etc); the ability to transform images from a vertical to a horizontal plane (such as from the blackboard to the desk surface).

  • Ocular Health: Evaluate ocular components to determine if any ocular pathology is present.


Vision screenings will not give the person administrating the test a complete picture of that individual. During a comprehensive eye examination an eye-care provider will take into consideration a patient's medical history. A person with systemic complications has a greater risk of having ocular complications such as with diabetes, hypertension, high cholesterol, and cardiovascular accidents. Even people who have had a concussion or a traumatic brain injury may have associated ocular changes that they are unaware of because of the complexity of their case. An eye-care provider will also take into consideration a patient's medication. Some medications have a side effect of vision loss with long-term usage, such as Plaquenil. While other medications can cause ocular dryness, such as histamines or anti-depressants.


What about a thorough family history? Yes, just like everything else genetics can play a role in our eyes. This can range from refractive status (myopia, hyperopia, astigmatism) to ocular health to ocular posture.


Vision screenings are designed to determine who needs a comprehensive eye examination. Unfortunately there are limitations to a vision screenings as well as variability. A vision screening should not replace a comprehensive eye examination. A comprehensive eye examination will evaluate ocular health, ocular posture, visual acuity, refractive status, and other ocular skills that are important in daily activities. Get your eyes checked with an eye-care professional!


An eye exam at Artisan Optics in Boise Idaho is more than just reading an eye chart.

Posted by Artisan Optics at 9/16/2016 5:34:00 PM
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