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Q&A: Ask the Expert: Vision Screenings & When to Refer for a Developmental Vision Evaluation: What Every OTR Should Know - featured May 26, 2011

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Q&A: Ask the Expert: Vision Screenings & When to Refer for a Developmental Vision Evaluation: What Every OTR Should Know

By: Carole L. Hong, OD, FCOVD

Why are vision screenings important?

An undetected vision problem may interfere not only with a child's ability to see clearly, but may also affect one’s ability to learn in school, interpret what they see and use their eyes to guide movement. Understanding the components of a thorough vision screening and collaborating with an optometrist that can provide developmental vision care can be critical to your clients’ success. The earlier a vision problem is diagnosed and treated, the less it will impact an individual's quality of life.

Why isn’t 20/20 visual acuity “perfect” vision?

Eyesight is the ability to discriminate the differences between small things. So although many think that 20/20 is perfect vision, that’s the farthest from the truth. All that it means is at 20 feet you can see what most people can see at that distance. This measurement gives NO information concerning how much effort is needed to see single, clear images, how well the eyes track along a line of print or if they work together properly for long periods of time (such as throughout the school day). There are more than 15 visual skills critical to vision and learning and seeing clearly (visual acuity) is just one of those skills.

What kind of problems do most vision screenings identify?

Most vision screenings performed by a pediatrician, school nurse or volunteer typically only tests for distance visual acuity. While the ability to see clearly in the distance is important, it does not give any indication of how well the eyes focus up close, track or work together. It also does not give any information about the health of the eyes.

Therefore, if you understanding the common signs and symptoms that indicate a potential vision problem that may hinder reading, learning and/or motor performance, you can sometimes identify a person that is in need of developmental vision care faster than performing a screening.

The five most common symptoms are:
  • Frequent loss of place when reading
  • Sloppy handwriting
  • Eye fatigue or headaches after reading
  • Avoidance of close work
  • Attention problems

A complete list of symptoms is available at

What should the occupational therapist evaluate in their vision screening?

Visual Acuity – Be sure to check near point vision as well as distance. Reading occurs between 10-18 inches from our eyes (depending on the age and size of the individual). Many children are farsighted which means they will pass the distance vision test with flying colors yet they will have difficulty seeing up close.

In measuring visual acuity, you may find reduced vision in one eye, a condition called Amblyopia, which can be secondary to strabismus (eye turn), anisometropia (unequal prescriptions between the eyes, such as when one eye is more farsighted than the other eye), congenital cataracts, or a sight threatening condition. This is one of the main reasons that the public health program, InfantSEE® was developed to examine, at no cost, babies (ages 6 to 12 mos.) for this potential vision condition.

Eye Teaming- The ability to use both eyes together smoothly, equally, simultaneously, and accurately. All judgments of spatial localization, depth perception and the accuracy of a single clear image depend upon this paired action of the eyes.

There are two ways to screen for problems of eye teaming. Instructions can be found on how to perform the Red Lens Near Point of Convergence Test at . A demonstration video can be found at

Another important test is the Cover Test and instructions for performing this can be found at The Cover Test will help to determine the absence of Strabismus, a misalignment of the two eyes, which affects approximately 4% of children. Strabismus is the main cause for poor depth perception or lack of 3D vision.

Eye Movement Control- Accurate fixation, the ability to maintain eyes on a target, pursuits, the ability to follow a moving target, and saccades, the ability to look from one target to another. One method of evaluating tracking skills is to use the NSUCO Eye Movement Test.

Visual Motor Integration- Eye-Hand coordination and how a child uses his or her visual system to help guide their motor system. A screening might include copying a triangle, divided rectangle and diamond or copying a sentence to view spacing and organization on a page. The key here is that the eyes need to guide the hand and or body, so make sure all the components for success are working by referring for a developmental eye exam.

Where can I find additional resources to learn more about how to do a vision screenings?

A. From Eyesight to Insight: Visual/Vestibular Assessment & Treatment presented by Carl Hillier, OD, FCOVD and Mary Kawar, MS, OT/L:

B. Vision Screening & Vision Rehab Therapy Seminar for Therapists by Dr. Laurie Chaikin, O.D., OTR/L, FCOVD:

C. VERA™ (Visual Efficiency RAting) is a highly effective vision screening and referral program developed by eye doctors, school nurses and educators:

When a child fails the screening what should we do?

The screening noted above may more thoroughly evaluate visual skills than a routine eye exam will, so it is vital that when a child fails this screening that the parents are referred to the correct eye care professional.
It is also important to make sure that the parent understands why you are making the referral and what questions they should ask when they see the doctor. For example, because not all eye doctors work with children, especially those that are on the spectrum, have attention difficulties or sensory processing problems, it is important for parents to call their eye doctor's office and ask the following two questions:
  1. Do you test for learning-related vision problems?
  2. Do you provide an in-office vision therapy program when indicated, or will you refer me to someone who does?

If the answer is no to either one or both of these questions, visit the Web site for the College of Optometrists in Vision Development,, to find the closest developmental optometrist.

Featured Author and Organization: Carole L. Hong, OD, FCOVD and the College of Optometrists in Vision Development (COVD)

Dr. Hong is residency trained and board certified in vision development and has been practicing for over 20 years in San Carlos, California. She often collaborates with OT’s, PT’s and SLP’s and provides excellence in children and adult vision care. Her practice has an emphasis on vision and learning; as well as, treatment of vision problems of those with special needs, strabismus (eye turns) or amblyopia (lazy eye,) head injury and stroke. She is an adjunct professor at SUNY State College of Optometry and Vice President of the College of Optometrist in Vision Development (COVD). She can be reached at (650) 593-1661 or

About COVD

The College of Optometrists in Vision Development (COVD) is an international, non-profit optometric membership organization that provides education, evaluation and board certification programs in behavioral and developmental vision care, vision therapy and visual rehabilitation. The organization is comprised of doctors of optometry, vision therapists and other vision specialists. For more information on learning-related vision problems, vision therapy and COVD, please visit or call 888.268.3770.

Tags: Article Visual Perception Vision Newsletter 27 May 2011 OT