A comprehensive eye examination should include the testing of these important binocular visual skills:

Tracking: the ability to move the eyes across a sheet of paper

Fusion: the ability to use both eyes together at the same time

Stereopis: binocular depth perception

Convergence: the ability of the eyes to move and work as a team

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What are some problems and symptoms associated with binocular vision or eye teaming problems?

-	Double vision
-	Eyestrain and headaches after reading for a short period of time
-	Intermittent blur
-	Inability to concentrate when reading
-	Short attention span
-	Frequent loss of place when reading
-	Rubbing or closing an eye
-	Words moving on the page
-	Good decoding skills but poor comprehension

 

Binocular Vision

Binocular vision is vision in which both eyes are used together. The word binocular comes from two Latin roots, bini for double, and oculus for eye. Having two eyes and binocular vision provides at least four advantages over having one. First, it gives an individual a spare eye in case one is damaged. Second, it gives a wider field of view. For example, a human has a horizontal field of view of approximately 180 degrees with two eyes but only 150 degrees with one. Third, it gives “binocular summation” in which the ability to have better vision quality using two eyes vs. only one eye. Fourth it can provide “stereopsis” in which parallax (slightly different angle of view) provided by the two eyes' different positions on the head give precise depth perception. Healthy binocular vision produces important visual perceptual skills which are part of normal human vision.

Problems with binocular vision can result in a number of functional deficits including; double vision, headache, eye strain, intermittent blur, poor depth perception, slow reading speed, and poor reading comprehension, among others.

Binocular vision impairment is any visual condition wherein binocular visual skills are inadequately developed. Binocular vision impairments often result in partial or total loss of stereoscopic vision and binocular depth perception. Conditions where the eye is obviously turned or crossed are commonly referred to with terms like "cross-eyed", "crossed-eyes", wall-eyes" or "wandering eyes". These binocular vision impairments are termed “strabismus” and are easily detected by others as all the observer needs to do is notice that both eyes do not aim in the same direction at all times. Other medical conditions which can contribute to poor binocular vision are anisometropia (large difference in prescription between the two eyes), astigmatism, nearsightness (myopia), and farsightedness ( hyperopia).

PLEASE NOTE: Some binocular vision impairments are not easily detected by parents, teacher or others because the turning or straying of the eye(s) is NOT obvious or consistent. Some eye turns are intermittent (they come and go) and/or they are not easily noticed by the untrained observer. A binocular vision problem may be present even when an eye turn is not apparent. That's why early comprehensive examinations are so important.

Two of the most common binocular vision problems:

• Convergence Insufficiency (CI)
  Convergence Insufficiency is an eye teaming problem in which the eyes have a strong tendency to drift outward when the individual is reading or doing close work. If the eyes actually drift out, the person may experience double vision or ignores one eye. To control this, the individual must exert excessive effort to reposition the eyes.
• Convergence excess (CE)
  Convergence excess is an eye teaming problem in which the eyes have a strong tendency to drift inward when the individual is reading or doing close work. If the eyes actually drift in, the person may experience double vision. To control this, the individual must exert excessive effort to realign the eyes.

How common are eye teaming problems?

Approximately five to ten percent of children and adults have binocular eye teaming problems which are significant enough to cause symptoms or complaints.

Binocular vision problems can show up at virtually any time in life. Children often experience issues relating to binocular vision problems while in school. However, they will rarely complain specifically about them. Most often poor school performance, avoidance of reading, complaints of headaches, etc. may be the first hint. Adults can also develop binocular vision problems. Symptoms are the best clue (see listing of symptoms). Those who spend extended time working on computers or those who do excessive reading and near work are more prone to be become aware of binocular vision problems. Finally, seniors also can experience binocular vision problems. Most commonly vertical eye muscle imbalances can develop during the “golden years”. Proper diagnosis and management by your doctors at NSVC will address your binocular vision problems.

Treatment of Binocular Vision Problems

Following the diagnosis of a binocular vision disorder, your doctor at NSVC will present appropriate treatment options to remedy the situation. These may include glasses (task specific perhaps to reading or computer work), prism glasses prescriptions, modification of your school or work ergonomic environment, and vision therapy.

Vision Therapy

Vision Therapy (VT), also is known as orthoptics, is a treatment method to better control the function of our eye muscles and focusing mechanism. Through the use a multiple biofeedback-like exercises, your vision system gains control and function of various skills such as; muscle alignment, convergence, accuracy and sustaining of clear comfortable near focus, and improved eye tracking skills. Visual disorders that can be improved with vision therapy are wide-ranging. Deficiencies in focusing skills, eye teaming, strabismus (crossed eye), amblyopia (lazy eye) as well as vision related learning problems could all benefit from therapy, no matter how longstanding the problem. Vision therapy isn't just about strengthening weak eye muscles, but rather, treats deficiencies, which prohibit the patient from achieving optimal comfort and efficiency. VT can be office based, home based, or a combination of the two. We may use computer based programs in our VT treatments. Your treatment plan is individually specified by our doctors to allow you to achieve success in the most efficient period of time possible. Compliance with therapy is the key to success. Vision therapy is considered medical treatment, and therefore may be covered under a major medical plan. We will be happy to write a letter for predetermination of benefits as well as provide any additional documentation required.

To discuss your eye care further or to schedule an appointment, please contact us: Deerfield (847–412–0311) | Park Ridge (847–823–8283) | Schedule an Appointment Online For emergencies, please call our office for instructions—one of our doctors will respond promptly.