Optometric vision therapy is an individualized treatment program designed to improve overall visual function and performance. Its proven results are derived from vision-based neurological and neuromuscular conditioning over time. When provided by a knowledgeable optometrist, vision therapy results in quantitative improvements in visual and visual information processing skills and, perhaps more importantly, an improvement in quality-of-life due to decreased symptoms and improved performance.

Many functional vision problems can be significantly improved through optometric vision therapy. It is a treatment modality for disorders including, but not limited to:

• Ocular motility dysfunction – eye movement disorders
• Vergence dysfunction – inefficiency in using both eyes together
• Strabismus – misalignment of the eyes
• Amblyopia – lazy eye
• Accommodative disorders – focusing problems
• Visual information processing disorders
• Visual sensory and motor integration
• Visual rehabilitation after traumatic brain injury which results in inefficient visual information processing (e.g., stroke)

These visual conditions are best treated with optometric vision therapy, which enables an individual to learn more efficient ways to perform visually. Optometric vision therapy can improve visual function much like physical therapy can improve general motor function.

Optometric vision therapy, also referred to as visual training or orthoptics, is an established, medically necessary therapy when prescribed by a  developmental optometrist. Clinical tests are administered to determine the presence of visual deficiencies. If optometric vision therapy is indicated, the optometrist recommends a specific treatment plan for the individual.

Optometric vision therapy plans typically involve a programmed combination of office treatment and home therapy. Lenses, prisms, optical instruments, and specially adapted computers are some of the devices through which one learns to use vision more effectively. The specific materials are less important than the feedback provided to the patient to enable change. Visual skills need to be developed until they become automatic and integrated with other visual as well as cognitive skills. As with most therapeutic treatments, the extent of success is also linked to patient compliance.

The principal benefits of optometric vision therapy, which include improved visual information processing and the ability to sustain visual function over time, are as applicable to the child in the classroom as they are to the adult using a computer or reading a book.

Without efficient visual skills the act of reading can be very frustrating. To the child with learning-related vision problems—often called a “hidden disability”—these frustrations can spill over into behaviors that can present themselves in a fashion similar to ADD/ADHD or dyslexia.

Some of the common symptoms relieved through vision therapy include:

• Eye strain
• Visually induced headaches
• Inability to concentrate when doing visual tasks
• Errors such as loss of place or reversals when reading or writing
• Homework battles

 More often, individuals have no recognized symptoms due to their avoidance of visually demanding tasks or an adaptation that decreases their performance. 

Optometric vision therapy also facilitates appropriate visual development, and serves as a component of the multi-disciplinary effort following stroke or head injury.

As part of routine school health assessments, children’s eyesight is commonly tested in school vision screenings. However, passing a school vision screening does not guarantee the absence of a vision problem. These screenings are typically limited in scope to reading letters on a distance eye chart and are not intended to replace a comprehensive vision evaluation that can detect vision based learning problems. In fact, many times these important vision disorders routinely evade detection.

It is estimated that 35-40% of all children with learning disabilities have visual problems. Specifically, at least 20% of individuals with learning disabilities have been found to have prominent visual information processing problems, and 15-20% of them have problems with visual efficiency skills.

Without efficient visual skills the act of reading can be very frustrating. To the child with a vision based learning problem—often called a “hidden disability”—these frustrations can spill over into behaviors that can present themselves in a fashion similar to attention deficit disorders such as ADD/ADHD, or reading problems such as dyslexia.

Prevention of vision problems and their consequences require timely detection. The College of Optometrists in Vision Development (COVD) recommends that all children receive a thorough professional eye and vision examination, particularly one that includes a comprehensive assessment of visual information processing and binocular function. A child should have a developmental vision assessment at age 3 and again at age 5 prior to entering school to monitor vision development. School vision screening alone are not sufficient for investigation of visual function for school-aged children.

Vision skills are a group of neuro-muscular activities which are learned and developed. These skills involve moving, focusing and teaming the eyes so they may function efficiently. Vision skills include several components.

Fixation is the ability to direct and maintain steady, central visual attention on a target. This basic skill is developed in infancy and refined through the early years. Ocular motor skills are the neuro-muscular control skills developed to point the visual system on target and move it to either follow a moving target (pursuit eye movements), or jump from one object to another (saccadic eye movements). The infant reflexively turns the entire upper torso toward the direction of a noise, and then gradually learns to turn only the head to guide the visual system. Through the toddler years the individual refines this movement system by learning to use eye muscles to replace head movement—an achievement important in visual readiness for school. Eventually vision becomes the dominant sense.

Accommodation (eye focusing) is another vision skill involving focusing the light entering the eyes. This combined lens neuro-muscular system is a network integrating the eyes and the brain. Accommodation is developed rather well by age three and further accuracy is achieved throughout the early years of development. This function deteriorates with age, causing the need for bifocals and/or reading glasses beginning at about age forty.

Binocularity (eye teaming) allows for coordinated eye movements as targets move from distance to near. This skill has a sensory and motor aspect. The sensory aspect is the brain’s ability to put what each eye sees together. This gives information on location (depth perception). The motor aspect involves convergence, where the eyes are turning in together and divergence, where the eyes are turning out together. This component allows both eyes to remain on the target as it moves closer and further from the eyes.

Optometrists evaluate the development, function, and efficiency of these vision skills. Poorly developed or abnormal function of vision skills results in inefficient visual performance and/or symptoms of fatigue or discomfort. 

This may have a negative impact on performance in school, the work place, sports, and activities of daily living. When properly diagnosed these visual inefficiencies can be effectively remediated with prescription lenses, prisms and/or vision therapy.

The symptoms typically caused by vision skill deficiencies include seeing double, losing one’s place with reading, poor or slow reading ability, discomfort (eye strain or headaches) with sustained use of the eyes, clumsiness, and poor performance in sports.

Difficulty processing visual information when reading, using computers or performing any sustained visual activity might also be attributable to vision skill problems.

Problems of letter and number reversals in children have concerned parents and educators for many years. Some have considered reversals as a symptom of dyslexia. More commonly reversals reflect a lag in spatial development. Most research has shown there is no structural or medical basis for these reversals. Although reversals are common and expected in five to six year old children, they may persist through childhood. Some adults may even continue to manifest these problems.

For many years, scientists have studied children with reversal problems, particularly regarding orientation to right and left as related to their own bodies (laterality), and to objects around them (directionality). At three, or even younger, the child should have grasped the concept of top and bottom, and right side up or upside down (even though still looking at books upside down). The four year old is grappling with front and back, and may still put a shirt on backward. Many four year olds show reversals as they put on shoes by themselves. Some four to five year olds may start printing numbers and letters from right to left. At these ages, this is a normal stage of developing orientation in children.

Although most children master this concept of directionality by age seven, this confusion in orientation may continue, in some people, all their life. Reversals are a manifestation of a developmental lag in the process of orientation. They are indicative of an underlying problem in the integration of the vestibular and visual systems in the brain. Rote repetition of learning to write letters and numbers correctly or rotely learning right and left hands may help us pass a test, but it does not solve the problem of the underlying causative factor of delayed orientation development.

The development of orientation starts in the prenatal period with the attitudinal reflexes which help the fetus orient in utero. This development continues through varied learned experiences in our lives. Interferences in movement activities involving vision and neuromotor relationships limit the development of orientation. According to the neuroscientist J.D. French, orientation contributes in an important way to the highest mental processes–the focusing of attention, and the ability to think, to learn, and to act.

Specific vision therapy, including the unique application of lenses and prisms during visual-neuromotor activities (movement with awareness and feedback), provides learning experiences to improve the development of laterality, directionality and orientation, and the related problems of reversals. When a child learns to orient easily, the evidence points to a well integrated and effectively operating person.

Patients diagnosed as having myopia are considered “nearsighted” because they see things more clearly up close than far away. The causes of and treatments for myopia are complex.

Clinical science has established that there are at least three forms of myopia. Type I myopia is present at birth or develops shortly thereafter in one or both eyes. This is typically a more severe form of myopia and less influenced by how we use our eyes. 

Type II myopia is acquired or functional myopia. When acquired at a young age, this myopia may be due to heredity, but its development depends on environmental influences. 

Type III myopia, associated with disease conditions such as diabetes, is rare and transient. It is often due to swelling of the major optical elements of the eye – the cornea or the lens.

Research has shown that the degree of Type II (functional) myopia experienced by some patients is a result of their response to visual demands. Extended periods of reading or viewing computer screens for sustained periods of time, with little physical activity, encourages the progression of nearsightedness at virtually any age. Over time the eyes focusing mechanism shifts inward, sacrificing distance clarity for near clarity.

Functional myopia usually develops gradually. Initially it may be noticed as a temporary blurring when shifting focus from near to far distances. Then the blur becomes prominent at the end of a school or work day. This cycle repeats itself until the blur at distance is constant. Children will have trouble copying from the board; adults will be aware of blurred road signs when driving home.

A comprehensive vision evaluation and appropriate supplementary testing are needed to determine which form of treatment for your nearsightedness is most appropriate. The prescribing of compensatory spectacle or contact lenses solely to make distance vision sharper treats the symptom rather than the cause of the problem. Although this may be appropriate in some cases, developmental or rehabilitative lenses may be indicated to address the underlying causes. These spectacle or contact lenses may incorporate prism, bifocal, or progressive addition lenses.

Optometric vision therapy is a program of care used to develop, restore, or enhance visual function and performance. The procedures are conducted under the supervision of an optometrist and are individualized to meet the needs of each patient. Depending on the case, vision therapy is prescribed to develop or remediate fundamental visual skills and abilities; improve visual comfort, ease and efficiency; and/or enhance how a person cognitively processes visual information and uses it to direct and monitor actions.¹

Vision therapy is generally conducted in-office, once or twice weekly for 30 minutes to an hour, often supplemented with procedures done at home between office visits. The goal of optometric vision therapy is to automatize normative function, not to strengthen eye muscles. It should not be equated with self-directed programs of eye exercises marketed to the public. Many specialized procedures and equipment are used in vision therapy programs including therapeutic lenses and prisms (regulated by state licensure.) Optometric vision therapy is a blend of medical, developmental and behavioral therapies which may include:

• Pursuit and saccade therapy (to improve the speed and accuracy of eye movements)

• Visual-vestibular therapy (to integrate eye movements with balance)

• Visual perceptual therapy (to enhance visual information processing)

• Eye-hand coordination therapy (to develop visually guided movement)

• Accommodative therapy (to enhance focusing stability, flexibility, and comfort)

• Visual attention therapy

• Peripheral awareness therapy (enhances the use of vision as a simultaneous sense, synchronously receiving and processing multiple inputs)

• Visual-spatial awareness including laterality, directionality, and visual imagery

• Visual-auditory integration

• Orthoptics (mechanics of eye movements)

Although optometric vision therapy evolved from orthoptics, orthoptics is only one of many therapies which are used in contemporary optometric vision therapy.² Orthoptics, which literally means straightening of the eyes, is limited to eye exercises to treat eye coordination problems by increasing the range of binocular fusion. The treatments used during optometric vision therapy go beyond the limited definition and scope of orthoptics to treat disorders of the visual system, indicative of vision as a collaboration between the eyes and the brain.³

In summary, optometric vision therapy is a complete program of habilitative and rehabilitative therapeutic vision care of which orthoptics is a subset. Optometric vision therapy is not synonymous with orthoptics.

1 www.aoa.org/documents/DefinitionsOptometricVisionTherapy.pdf. Accessed June 13, 2007.

2 Press LJ. The evolution of vision therapy. In: LJ Press, ed. Applied Concepts in Vision Therapy. St. Louis: Mosby 1997.

3 www.aoa.org/x5417.xml. Accessed June 13, 2007.

Attention deficit hyperactivity disorder (ADHD) is a neurological disorder that impacts the parts of the brain that help us plan, focus on, and execute tasks. ADHD symptoms vary by sub-type — inattentive, hyperactive, or combined — and are often more difficult to diagnose in girls and adults. Here, we review the symptoms, causes, types, and tests associated with attention deficit hyperactivity disorder.

BY ADHD EDITORIAL BOARD, Additudemag.com, MEDICALLY REVIEWED BY WILLIAM DODSON, M.D. ON SEPTEMBER 26, 2019

What Is ADHD? Meaning & Symptoms

ADHD stands for attention deficit hyperactivity disorder, a complex brain disorder that impacts approximately 11% of children and almost 5% of adults in the U.S.¹ ADHD is a developmental impairment of the brain’s executive functions. People with ADHD have trouble with impulse-control, focusing, and organization.

Neuroscience, brain imaging, and clinical research tell us a few important things: ADHD is not a behavior disorder. ADHD is not a mental illness. ADHD is not a specific learning disability.

ADHD is, instead, a developmental impairment of the brain’s self-management system. Common ADHD symptoms include:

• inattention
• lack of focus
• poor time management
• weak impulse control
• exaggerated emotions
• hyperfocus
• hyperactivity
• and executive dysfunction

Many patients and clinicians describe ADHD as an iceberg, where most symptoms lay hiding under the surface — out of sight but ever present. 

“Attention deficit” is, some experts assert, a misleading name. “Attention deregulation” might be a more accurate description since most people with ADHD have more than enough attention — they just can’t harness it in the right direction at the right time with any consistency. And so individuals with ADHD hyperfocus and lose track of time, or misplace their keys, or blurt out an unrelated thought when their focus breaks free from its chains.

What Causes ADHD?

The causes of ADHD remain somewhat unclear. Research suggests that genetics and heredity play a large part in determining who gets ADHD.2 However, scientists are still investigating whether certain genes, especially ones linked to the neurotransmitter dopamine, play a defined role in developing ADHD.

Additional research suggests that exposure to toxins and chemicals may increase a child’s risk of having ADHD.³

ADHD is not caused by bad parenting, too much sugar, or too many video games. ADHD is a brain-based, biological disorder. Brain imaging studies and other research show many physiological differences in the brains of individuals with ADHD.⁴

What Are the 3 Subtypes of ADHD?

The Diagnostic and Statistical Manual of Mental Disorders (DSM)5previously identified three types of ADHD:

• Primarily hyperactive-impulsive type
• Primarily inattentive type (formerly called ADD)
• Primarily combined type

People with hyperactive-impulsive subtype of ADHD act “as if driven by a motor” with little impulse control — moving, squirming, and talking at even the most inappropriate times. They are impulsive, impatient, and interrupt others.

People with the inattentive subtype of ADHD are easily distracted and forgetful. They may be daydreamers who lose track of homework, cell phones, and conversations with regularity.

Individuals with combined-type ADHD display a mixture of all the symptoms outlined above.

These subtypes are now considered “presentations” in the most recent version of the DSM, the DSM-V. Researchers determined that people often move from one subtype to another. For example, a child may present as primarily hyperactive-impulsive in preschool, and  lose much of the hyperarousal in adolescence to fit the primarily inattentive presentation. In college and adulthood, the same individual may transition to combined presentation.

The subtypes were primarily based on overt behavioral symptoms, and ignored less visible symptoms like emotional dysregulation, cognitive patterns, and sleep difficulties. Behavioral symptoms imperfectly capture the defining features of ADHD. Non-behavioral characteristics are increasingly recognized in research and diagnosis.

What Are the Symptoms of ADHD?

The symptoms of ADHD are spelled out in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), which lists nine symptoms that suggest ADHD–Primarily Inattentive and nine that suggest ADHD–Primarily Hyperactive/Impulsive. A child may be diagnosed with ADHD only if he or she exhibits at least six of nine symptoms from one of the lists below, and if the symptoms have been noticeable for at least six months in two or more settings — for example, at home and at school. What’s more, the symptoms must interfere with the child’s functioning or development, and at least some of the symptoms must have been apparent before age 12⁶. Older teens and adults may need to consistently demonstrate just five of these symptoms in multiple settings.

What Are the 9 Symptoms of ADHD – Primarily Inattentive Type?

• Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or during other activities (e.g., overlooks or misses details, work is inaccurate).
• Often has difficulty sustaining attention in tasks or play activities (e.g., has difficulty remaining focused during lectures, conversations, or lengthy reading).
• Often does not seem to listen when spoken to directly (e.g., mind seems elsewhere, even in the absence of any obvious distraction).
• Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., starts tasks but quickly loses focus and is easily sidetracked).
• Often has difficulty organizing tasks and activities (e.g., difficulty managing sequential tasks; difficulty keeping materials and belongings in order; messy, disorganized work; has poor time management; fails to meet deadlines).
• Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (e.g., schoolwork or homework; for older adolescents and adults, preparing reports, completing forms, reviewing lengthy papers).
• Often loses things necessary for tasks or activities (e.g., school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
• Is often easily distracted by extraneous stimuli (for older adolescents and adults, may include unrelated thoughts).
• Is often forgetful in daily activities (e.g., doing chores, running errands; for older adolescents and adults, returning calls, paying bills, keeping appointments).

What Are the 9 Symptoms of ADHD – Primarily Hyperactive-Impulsive Type?

• Often fidgets with or taps hands or feet or squirms in seat.
• Often leaves seat in situations when remaining seated is expected (e.g., leaves his or her place in the classroom, in the office or other workplace, or in other situations that require remaining in place).
• Often runs about or climbs in situations where it is inappropriate. (Note: In adolescents or adults, may be limited to feeling restless.)
• Often unable to play or engage in leisure activities quietly.
• Is often “on the go,” acting as if “driven by a motor” (e.g., is unable to be or uncomfortable being still for extended time, as in restaurants, meetings; may be experienced by others as being restless or difficult to keep up with).
• Often talks excessively.
• Often blurts out an answer before a question has been completed (e.g., completes people’s sentences; cannot wait for turn in conversation).
• Often has difficulty waiting his or her turn (e.g., while waiting in line).
• Often interrupts or intrudes on others (e.g., butts into conversations, games, or activities; may start using other people’s things without asking or receiving permission; for adolescents and adults, may intrude into or take over what others are doing).”

¹ “Data & Statistics.” Centers for Disease Control and Prevention. Ed. Center for Disease Control. Centers for Disease Control and Prevention, 14 Feb. 2017. Web. 14 Mar. 2017.

² Thapar, Anita, and Evangelia Stergiakouli. “An Overview on the Genetics of ADHD.” Xin li xue bao. Acta psychologica Sinica (Aug. 2008) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2854824/

³ Philip J. Landrigan, Jordan Slutsky. Are Learning Disabilities Linked to Environmental Toxins? Learning Disabilities Worldwide. https://www.ldworldwide.org/environmental-toxins 

⁴ Dovey, Dana. “Doctors May Soon Be Able To Diagnose ADHD With An MRI Scan.” Medical Daily. IBT Media Inc., 30 Apr. 2014. Web. 14 Mar. 2017.

⁵ Association, American Psychiatric, ed. Diagnostic and Statistical Manual of Mental Disorders: DSM-5. Washington: American Psychiatric, 2014.

⁶ Association, American Psychiatric, ed. Diagnostic and Statistical Manual of Mental Disorders: DSM-5. Washington: American Psychiatric, 2014.

Updated on March 5, 2020

After analyzing a nationally representative sample of children, researchers found that children with vision problems not correctable with glasses or contacts may be twice as likely to have ADHD.

BY JANICE RODDEN, Additudemag.com

April 28, 2016

A study, published in the journal Optometry and Vision Science sought to compare the incidence of ADHD in children who can see normally, and those with vision problems which cannot be corrected with glasses or contacts. Examples of this type of vision problems include disorders of eye alignment (crossed eyes) or eye movement (nystagmus). They found that, after adjusting for other factors known to be associated with ADHD, children with vision problems were nearly two times more likely to have ADHD.

The researchers, led by Dawn K. DeCarlo, OD, MSPH, FAAO, of University of Alabama at Birmingham, analyzed data from the cross-sectional 2011-2012 National Survey of Children’s Health, conducted by the U.S. Centers for Disease Control and Prevention. The sample included 75,171 children between age four and 17. Telephone interviewers asked parents about the child’s vision as assessed by a health care provider, ADHD, intellectual impairment, and condition severity.

The results showed that 15.6% of children with vision problems had ADHD, while only 8.3% of children with normal vision had the condition — 1.8 times more likely. For children with moderate vision issues, the rate was even higher — 2. 6 times higher prevalence. After a multivariable analysis adjusting for confounding variables, vision problems were still independently associated with ADHD regardless of patient and family characteristics.

“Children with vision problems should be monitored for signs and symptoms of ADHD so that this dual impairment of vision and attention can best be addressed,” concluded Dr. DeCarlo and the other researchers.

Journal Reference:

1. Dawn K. DeCarlo, Mark Swanson, Gerald McGwin, Kristina Visscher, Cynthia Owsley. ADHD and Vision Problems in the National Survey of Children’s Health. Optometry and Vision Science, 2016; 93 (5): 459-465. DOI: 10.1097/OPX.0000000000000823

Updated on April 6, 2017