"Many parents today are under the impression that the vision screening their children receive from the school nurse is sufficient," says Jeffrey R. Anshel, DS, OD. "The screening [at school] will determine the child¹s distance vision but what is missing is the near vision. Very few eye screenings include this much-needed exam. Just as children should visit the pediatrician and the dentist, they should also see a licensed eye care provider to screen for vision problems."
A comprehensive eye exam includes testing and evaluation of visual skills (function, performance, etc. In the absence of complete testing, common pediatric vision problems can go undetected, and, in some cases, can be misdiagnosed as a learning disability or behavioral problem. This page lists some of the visual skills which need to be evaluated as part of a child's comprehensive vision examination.
IMPORTANT NOTE: Many school eye or vision screenings test only one of the visual skills listed below -- that is, Acuity-Distance (clarity of sight in the distance, 20/20 eyesight as measured by the standard Snellen eye chart).
A child's comprehensive eye examination should include testing of the following visual skills, ALL of which are important aspects of normal, healthy human vision.
Acuity - Distance Vision: visual acuity (sharpness, clearness) at 20 feet 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, etc.
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.)
Visual Memory: the ability to store and retrieve visual information.
Visual Form Discrimination: the ability to determine if two shapes, colors, sizes, positions, 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).
Remember: an eye exam that tests distance vision only is NOT an adequate evaluation of a child's visual development. The visual skills listed above contribute significantly to a child's success with reading and school achievement. Learn more at Success in School: 20/20 Eyesight is Not Enough!
Below are some common pediatric visual conditions which are not detected through the 20/20 eye chart test alone:
Amblyopia: See What is Amblyopia or Lazy Eye.
Hyperopia: a refractive condition that makes it difficult to focus at near viewing distances (i.e., reading distance).
Strabismus (Deviating Eyes): See What is Strabismus?
Convergence Insufficiency Disorder: See Common Cause of Blurred Vision at Near, Double Vision, Intermittent Exotropia, Sleepiness or Headaches While Reading, Losing Place While Reading, etc.