August is National Children’s Vision and Learning Month 2007. In recognition of this important Public Awareness Campaign, EXCELerated Vision presents the following article, written by Barry Tannen, O.D.,FCOVD, FAAO, a leading expert in the field of children’s vision. Dr. Tannen lectures nationally and internationally on learning related vision disorders, strabismus, amblyopia and vision therapy.
Could it be a Vision Related Learning Problem?
Barry Tannen, O.D.,FCOVD, FAAO
The Myth of 20/20 Eyesight
What do you think of when you hear the words ÛÏperfectÛ vision? If you’re like most people the first thing that comes to your mind is 20/20 eyesight. But what does 20/20 eyesight really mean?
In 1862, a man named Snellen devised a testing system to determine people’s eyesight. He asked people to stand at 20 feet and through experimentation discovered the smallest sized letter that most people with good eyesight could see. He called this a size 20 letter and the vision was recorded as 20/20. At the time it was thought that this was all you needed in the way of vision. Actually it was a great breakthrough at the time. Now, almost 140 years later, we have made quantum leaps in our knowledge of the human visual system. Yet, many times the old 20/20 standard is still the way that vision is tested.
How Does Vision Affect Learning?
20/20 eyesight tells us how well we can see to drive or to see a blackboard. It tells us if we can see a newspaper or a computer screen. But there are many things 20/20 eyesight will never tell us. Learning related vision problems are those in which a vision condition can impair a childÛªs ability to read with comfort and efficiency and therefore interferes with the ability to perform in the classroom. What are some symptoms of a learning related vision problem that wonÛªt show up in a 20/20 eye chart test?
- Blurred vision that comes and goes
- Double vision, especially when reading
- Headaches after reading, studying or working on a computer
- Loss of place of skipping or words when reading
- Tired, strained eyes
- Excessive blinking or rubbing of the eyes especially when reading or studying
- Take an hour to do 30 minutes of homework
- Avoidance or reading or studying
These are some symptoms of a potential vision problem that can interfere with your childÛªs learning even if they have 20/20 visual acuity.
What is a Learning Related Vision Problem?
Vision is a complex process that involves eye tracking, focusing, and eye teaming among others. The ability to sustain focus and shift focus back and forth is called accommodation. This visual ability can become impaired in children and adults. Imagine looking at a newspaper and having it go in and out of focus hundreds of times a day. Your child experiences this countless times as he looks from his desk to the teacher in the front of the room. Wouldn’t that be uncomfortable? That’s the way it can look for someone with an accommodative or focusing disorder.
The ability to keep the two eyes perfectly aligned on a book or other near-point work is called eye teaming or binocularity. This is a visual ability that often becomes impaired in children and adults. Do you know that even a relatively small amount of misalignment between the two eyes can cause double vision? Worse yet is that children rarely report that they see double. They may just say the print looks blurry or that their eyes hurt. Many times they say nothing at all, but just avoid reading all together. A common eye teaming problem that develops is convergence insufficiency.
The ability to follow sentences from word to word and line to line accurately, can become impaired or never develop properly in the first place. This is called an eye tracking problem. During our evaluations we use a computerized eye tracking instrument called a Visagraph that carefully monitors and records the child’s eyes while they’re reading. By doing this, we can get a precise simulation of how they track the words on a printed page including how their eye tracking and reading efficiency compares to other people of the same age. It is also a wonderful tool in helping parents to understand why their child experiences loss of place or skips words. Watching the regressions as the child reads and rereads the same line gives a clear understanding of why a simple homework assignment can take hours.
What can be done?
After a thorough vision evaluation by a developmental optometrist, some children are found to be able to benefit by a vision therapy program. Vision therapy is a step by step program of care that helps restore the visual abilities of focusing, eye teaming and eye tracking. Using specially designed computers, lenses, prisms and 3D devices known as stereoscopes, we can many times help children or adults improve their visual abilities and greatly improve their reading and learning comfort and efficiency.
Learning problems often have multiple causes. Teachers, psychologists, reading specialists, occupational therapists, speech and language therapists, developmental optometrists, and other professionals often need to work together to help children reach their learning potential.
Not all eye doctors are trained in the diagnosis and treatment of learning related vision problems. If your eye doctor does not offer this form of evaluation and treatment, he or she may be able to refer you to an eye care professional that does.