Introduction To Behavioral Optometry & Developmental Vision Care
Visual Development and the Visual Process
Vision is one of our most wonderful and important gifts. It might surprise you to learn that the is not fully developed at birth. Hopefully, visual development continues as long as we do. Many factors influence visual development. And visual development influences many aspects of life, including child development. The visual process must continue to develop throughout our lives in order to keep up with the ever changing demands we face. Our bodies change, the nature and complexity of our education and work change over time, and the technology with which we interact continues to change much more rapidly than we have ever seen before.
Some still believe that the way we see is hereditary and therefore unchangeable. Nothing could be further from the truth. There is abundant evidence from many branches of science that development of the visual process is strongly influenced by the environment. That is, the variety of stimulation available, the demands we face and the problems we must solve in order to use our visual process all exert powerful influence on the direction our visual development will take.
The visual process is expected to continually develop and change throughout our lives to be at its best. Vision is not simply a thing done by the eyes. It is a complex process involving many areas of the brain, and usually various parts of the body including the eyes, head, neck, hands, arms and legs. As a dynamic process of intake and response, good visual performance must be learned and, if problems arise, can be improved with vision therapy and/or Lenses.
We must learn how to see just as we must learn to walk or to talk. However, it is much easier to learn walking and talking since we have access to examples. That is, we can watch someone walk and we can mimic the action – at first with some hand-holding, then on our own. We can hear and watch others talk – at first with much coaching then on our own. We cannot however learn how to use the visual process by watching or imitating others. Nobody else can see what you see. Even though the visual process is one of the most important things that helps bring individuals into closer contact with the world around them, it is, at the same time, a very personal matter. Few of us would be able to explain to someone what green looks like, how to make the words on a page clearer or just how to use their eyes better. I don’t know if a human raised without other humans around would walk or talk, but I can assure you that they would find a way to use their visual process to a reasonable degree.
Besides determining eye health, most eye exams are limited to measuring sight, which is only a small part of the visual process. Sight is to the visual process what having working leg muscles is to dancing. Clear sight is a basic tool within the vast, complex visual process. Similarly, working leg muscles are basic tools for the complex activity that is dancing. Interestingly, just as dance training can strengthen leg muscles, visual training can lead to improved eyesight (though this has very little to do with muscles), despite the fact that most eye doctors think this is impossible.
In the case of a school-aged child for example, sight merely allows us to see the chalkboard or the page on our desk while vision allows us to copy something from the board onto a piece of paper or to file the image in our mind – or both. The visual process enables us to derive meaning from what we see. Our responses to the information we process are also formulated and guided by the visual process. Vision has a powerful influence on how we think, learn, move, play and how we relate to ourselves and others.
The visual system, which includes the eyes and pathways to numerous parts of the brain, begins warming up in the womb as the eyes move around preparing for the day they can interact with the lighted environment. Soon after birth, the eyes and hands begin their job of relating to the surroundings by interacting with the people and objects that share our environment. At first, the hands do a larger portion of this investigating because the part of the visual system dedicated to fine detail is not fully developed (although details can be distinguished at short distances). The part of the visual system that is more developed at this time, peripheral vision, is concerned with motion occurring within the environment as well as our own movement and coordination. Peripheral vision deals with larger shapes and movement patterns, such as those of our caregivers, and has evolved as a survival mechanism to quickly recognize and respond to all aspects of our environment. The visual process has tremendous implications for overall development and behavior.
Visual skills and abilities
The basic mechanical skills of the visual system are: focusing, which is the ability to see clearly at any distance for any period of time with minimal effort, eye movements, which are important for following a moving object or looking from one object to another, as well as the ability to look at a single object, whether still or moving, for as long as is necessary, and eye teaming, which refers to both eyes pointing at the same thing at the same time; without this ability there can be confusion and disorientation in processing visual information for meaning and response. Other very important aspects of visual function are peripheral visual awareness and eye/hand coordination. Normal visual acuity, which we know as 20/20, is the ability to recognize a certain size letter at a certain distance. While this is typically the main focus of most eye exams, in the overall scheme of visual performance it is not nearly as important as we are led to believe. Many people with 20/20 eyesight have inadequate visual skills, leading to functional vision problems that seriously hinder, or prevent high-level performance. Peripheral visual awareness is the foundation on which all visual skills and performance are built. Peripheral vision guides the eyes in locating precisely where they both should aim; this in turn allows the eyes to move smoothly together from one place to another as well as giving information on where to focus so the object will be clear. If all of this is not working smoothly and automatically, a number of problems are likely to result. Decreased visual function can lead to difficulty with reading, handwriting, and copying from the board as well as reduced attention span, hyperactivity, fatigue, poor coordination, headaches and some types of motion sickness.
Eye Movements: Tracking is the ability to visually follow a moving target or switch attention from one object to another. Fixation is the ability to look directly and steadily at a specific object. These skills permit easy shifting of the eyes along the line of print in a book, a rapid and accurate return to the next line, and quick, accurate shifts between desk and chalkboard. Inadequate eye movement control may cause loss of place when reading, difficulty copying from the chalkboard, and skipping or omitting letters or small words when reading.
Focusing is another skill that is important for school performance. This skill allows rapid and accurate clarity as we look from one distance to another such as from desk to chalkboard. It also permits clear focus at the normal reading distance for appropriate periods of time. Signs of a focusing problem may include blurred vision, fatigue or headaches while reading, and inability to see clearly at distance after reading. This may lead to a form of nearsightedness that is preventable or correctable if properly diagnosed.
Eye Teaming is important in order to have comfortable vision. If the two eyes do not work together in a very precise and coordinated fashion, it can result in double vision (which usually goes unreported). There are several different types of eye teaming problems which can occur. In one common form, one eye may be seen turning in or out intermittently or even all of the time. Another common occurrence is for the image from one eye to be ignored by the brain because the images from the two eyes do not match well enough to combine into a single image, which may lead to what is known as a “lazy eye”. Most eye turns that disrupt efficient visual performance can go undetected without specialized testing because they are not cosmetically noticeable. Poor eye teaming can result in frequent loss of place when reading, words appearing to move on the page, poor handwriting, headaches or eyestrain. There will usually be an inability to stay at a visual task for any prolonged period of time. Poor eye teaming can also result in poor depth perception. This may contribute to motion sickness and poor general coordination, which can lead to dissatisfaction with, or avoidance of, sports activities.
Peripheral awareness is the capacity to be aware of, but not distracted by, the total visual environment while engaged in any specific task. It is the foundation of all the previously mentioned visual abilities. Peripheral vision can be significantly reduced by stress, causing a reduction in visual information processing. This stress response tends to continue even after the visual demand has ended and may become chronic. Sports performance, often an important aspect of social acceptance for the school-aged child, can be compromised by poor peripheral awareness. Signs of reduced peripheral efficiency include distractibility, decreased attention span, hyperactivity, and poor comprehension. Activities such as reading, writing, and copying from the board can also be adversely effected, as well as general coordination.
Eye/hand coordination refers to the ease and accuracy with which our eyes guide our hands to write, draw, make things, pour things, catch a ball, etc. While we typically think of our hands being responsible for such activities, it is really the eyes that are required to lead the hands into action. If the eyes are not accurately informing the hands, we cannot efficiently perform these types of activities.
Within a few years of birth our visual system must somehow be ready for learning to read. This is a fairly simple process for most of us. Significant problems often arise in a few more years when we must begin reading to learn. This is a much more complex process that requires effortless, comfortable visual performance especially in the areas of eye movements, focusing, eye teaming and peripheral vision. If the visual system is not working automatically it drains energy, which would otherwise be used for attending to, comprehending, and making use of visual information. The relationship between vision and learning is complex. We must be able to both keep our eyes still for periods of time and to move our eyes quickly and accurately from place to place countless times throughout the school day. We must be able to maintain clear focus for periods of time to investigate details and we must be able to shift focus quickly and accurately from one point to another countless times throughout the school day. We must be able to use our eyes effortlessly as a team at all times so that there is a normal 3-dimensional appearance to the world and good ability to judge distances and depth.
Solving visual problems
Many problems with eye teaming are thought to be correctable with surgery. While there is very little scientific evidence that this is the case, these surgeries are routinely performed on thousands of children every year. Success of such surgery is determined by a cosmetically acceptable appearance of the eyes as determined by the surgeon over a period of a few weeks. While this does frequently occur, in many cases this cosmetic alignment is only temporary and requires multiple attempts. Even then, there is no way to know how the eyes will ultimately align. Meanwhile, each operation creates more scar tissue, which causes reduced comfort and restricts the normal movement of the eyes. These surgeries also, by their very nature, severely disrupt the possibility of comfortable two-eyed vision in many cases, even though the eyes may appear straight. The basic problem with these surgeries is that they fail to account for the fact that the brain is the primary participant in vision, not the eyes. Most of these operations are performed on healthy eye muscles, which are misdirected due to perception problems within the brain – not faulty muscles.
An alternative, safer method of correcting such conditions is known as Visual Training or vision therapy. Vision therapy involves the dynamic use of lenses and prisms along with a comprehensive program of eye/mind/body exercises that enable a person to better observe, understand and utilize their vision in ordinary everyday activities. Vision therapy, provided by behavioral optometrists, has proven for over sixty years that many functional visual problems can be safely eliminated without surgery. In addition to the treatment of visual skills problems, behavioral optometrists, through the use of vision therapy, offer a dynamic approach to treating many cases of dyslexia, attention deficit disorder, hyperactivity and a wide variety of so-called learning disabilities. Experienced practitioners are also having good success with children suffering from Downs Syndrome, cerebral palsy and traumatic brain injuries as well as autistic and multiply-impaired children.
Vision therapy enables people to more fully reach their potential by removing visual obstacles while creating new functional patterns. Unlike invasive surgical procedures that are merely cosmetic and irreversible, vision therapy is a safe method of providing functional improvement. While functional improvement is the primary goal of any vision therapy program, cosmetic improvement is a common result of the process. Surgery is done to an anesthetized person but vision therapy is a dynamic process that involves the individual at every level, as she heals herself with the help of an experienced practitioner.
Vision is a dynamic process of obtaining information and creating meaningful and satisfying responses. It is a developed, learned and trainable process that has a wide spectrum of influence upon our lives. It can greatly enhance our ability to learn, work and have fun or it can be a major obstacle to these things. Vision therapy can offer a wide range of benefits for people of all ages, with all types of visual issues.
Find a behavioral optometrist near you if you are unsure about how well your child’s or your own vision is working or contact Dr. Gallop in Broomall, PA (Delaware County) for any specific questions you may have or to make an appointment.
Dr. Gallop specializes in working with people of all ages including children with learning problems, reading difficulties and children on the autism spectrum. He also works with people of all ages dealing with stabismus, amblyopia and acquired brain injury.
SOURCES
Gessell, Arnold. Ilg, F., Bullis, G. (1949). Vision: Its Development in Infant and Child. New York: Paul B Hoeber, Inc.
Wiener, Harold. (1977). Eyes OK I’m OK. San Raphael: Academic Therapy Publications.
Getman, Gerald. N. (1962; 1984). How to Develop Your Child’s Intelligence. White Plains: Research Publications.
Dr. Gallop practices in Delaware County at 7 Davis Avenue, Broomall, PA 19008; conveniently located for those in Ardmore, Bryn Mawr, Rosemont, Villanova, Radnor, Narberth, St. Davids, Wayne, Paoli, Devon, Berwyn, Newtown Square, Haverford, Havertown, West Chester, southern New Jersey, Philadelphia and its surrounding suburbs.
There are several organizations that can provide further information as well as help in finding behavioral optometrists in your area.
Optometric Extention Program Foundation www.OEPF.org
College of Optometrists in Vision Development www.COVD.org
Optometrists Network www.optometrists.org (more…)