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The Cause of Internet and TV Addiction?


Convergence Insufficiency


·        What is Convergence Insufficiency?

·        Symptoms

·        Aggravated By

·        Causes

·        Suggestions

·          Convergence Exercises (Orthoptics)

·         Near Point of Convergence Exercises:

·         Base-Out Prisms, Stereograms:

·         Computer Programs:

·          Base-In Prisms

·        More Definitions

·       Convergence Insufficiency and ADHD

·           Things to Consider

·           Related Topics


What is Convergence Insufficiency?

Simple Explanation of Convergence Insufficiency

"This is a condition in which the muscles of the eye responsible for convergence (turning the eyes in) appear to be weak, at least relative to the muscles responsible for divergence (turning the eyes out). However, the patient's eyes remain straight in all fields of gaze. This results in ‘strained’ eyes and the affected individual complains of

·          Headache,

·          Eyestrain,

·          Blurred vision, or

·          Fatigue

with continued efforts at near work. This condition most commonly occurs in teenagers and young adults, though it can occur up through middle age." Convergence Insufficiency


Detailed Explanation of Convergence Insufficiency

·          "Convergence insufficiency is a common condition that is characterized by a person's inability to maintain proper binocular eye alignment on objects as they approach from distance to near.

There is typically

·            The symptoms associated with convergence insufficiency vary from mild to severe, but they are often extremely troublesome for those patients with this condition, especially when associated with a small angle exotropia at the near working distance."

eMedicine - Convergence Insufficiency



Lack of Symptoms

”Many patients with objectively measured convergence insufficiency may not complain of symptoms. This usually occurs because of suppression of the nonfixating eye or avoidance of near vision tasks."

eMedicine - Convergence Insufficiency


Most Common Symptoms

"The most common symptoms associated with convergence insufficiency include asthenopia (eyestrain) and headache, diplopia [double vision], blurred vision, and moving of print."

eMedicine - Convergence Insufficiency


"…Fatigue, frequent loss of place when reading, and frank binocular diplopia associated with near point tasks are among the symptoms associated with this condition."

eMedicine - Convergence Insufficiency


"Patients typically present as teenagers or in early adulthood, complaining of gradually worsening eyestrain, periocular headache, blurred vision after brief periods of reading, and, sometimes, crossed diplopia with near work. It is not unusual for the patient to squint one eye while reading to relieve blurring or diplopia. Few, if any, symptoms are present at distance fixation.

eMedicine - Convergence Insufficiency


Eye Contact

"When the two eyes fail to work together as an effective team, performance in many areas can suffer (reading, sports, depth perception, eye contact, etc.)."

Vision Therapy


Aggravated By

"Symptoms are aggravated by illness, lack of sleep, anxiety, and prolonged near work."

eMedicine - Convergence Insufficiency


"The frequency of symptoms may increase with age as patients' ability to compensate for their relative divergent binocular alignment decreases with time. "

eMedicine - Convergence Insufficiency



Accommodative Insufficiency

"The causes of convergence insufficiency are not completely clear. A connection has been made between accommodative insufficiency and convergence insufficiency.

eMedicine - Convergence Insufficiency


"Accommodative insufficiency often is associated with convergence insufficiency and symptoms of asthenopia [eyestrain] and headache. This occurs as the patient tries to eliminate near vision blur by increasing accommodative effort. The increased accommodative effort results in increased convergence, which may be more than what is required for the near vision task, thereby resulting in an esophoria (as mentioned above). This also explains why the frequent accompaniment of blurry vision and diplopia with asthenopia and headache symptoms occurs."

eMedicine - Convergence Insufficiency


"This [eyestrain] most commonly occurs due to the sustained increased effort required to increase fusional convergence."

eMedicine - Convergence Insufficiency


·          Vision: Binocular Functions: Accommodative Insufficiency


Close-Up Work

"…Many patients with this disorder have vocational and/or avocational visual demands that require prolonged close-up work. The most common presentation encountered by a clinician is that of a high school or college student who develops symptoms when excessive demands are placed on the visual system during extended periods of studying."

eMedicine - Convergence Insufficiency



"A significant exophoria [A tendency of one eye to turn outward] at near with inadequate fusional convergence [the coordination of the separate images of the same object in the two eyes into one] appears to be the primary underlying problem."

eMedicine - Convergence Insufficiency




Animated Mouse Cursors, Waiting

I’ve found that Windows 98’s ‘science’ desktop theme is helpful for improving focus and reducing dissociation while using a computer. This theme has several features. One of the features replaces the ‘hourglass’ mouse cursor with an animated mouse cursor. (The ‘hourglass’ mouse cursor is displayed by the Windows operating system when the computer is busy.) The ‘science’ theme replaces this hourglass with a circle surrounding a dot. The dot is surrounded by lines which look like lightning strikes. These lines are helpful in attracting attention to the dot.

     Here is a photo of the ‘science’ mouse cursors: (note: I don’t recommend downloading from this site—their installation program attempts to install spyware, and requires you to install adware, on your computer)


·        Vision: Binocular Functions: Light Sensitivity: Suggestions: Customize Your Mouse Pointer

·        Other Suggestions: Distractions 

·        Newsgroup: microsoft.public.windowsxp.general: 'Old 9x Themes in XP' (for Windows XP users)



·          Vision: Three-Dimensional Stereo Images

·          Vision: Bates Method: Fusion

·          Vision: Bates Method: Accommodation: Examining Small Objects

·          Vision: Bates Method: Palming (for fatigue)

·          Vision: Bates Method: Palming: Palming with Visualization


Convergence Exercises (Orthoptic Therapy) and/or Base-In Prisms


"Convergence exercises (orthoptic therapy) and/or base-in prisms are the mainstays of treatment for convergence insufficiency.” Convergence Insufficiency


Convergence Exercises (Orthoptics)

Note: Please read the section Things to Avoid before trying these exercises.

Near Point of Convergence Exercises:

“An accommodative target, such as the point of a pencil (ie, pencil push-ups), is placed remote to the patient’s near point of_convergence and gradually brought toward the tip of the nose with the patient converging to avoid diplopia. Just before there is a break in fusion, the patient holds fixation on the target for 10 seconds. This so-called push-up is repeated 10 times, 2-4 times a day, until the patient is able to hold fixation to the tip of the nose. The exercises can be tapered and then used on an as-needed basis when the patient notices a recurrence of symptoms.”

eMedicine - Convergence Insufficiency : Article by Michael J Bartiss, OD, MD


“As previously mentioned, this condition is thought to be due to a relative imbalance in eye muscle strength.” Convergence Insufficiency


“Adding a small base-out prism in front of one eye may increase the intensity of the exercise." Convergence Insufficiency


·           Vison: Bates Method: Fusion


·        “Several other forms of convergence exercise involve the use of stereograms or recession from a target, to name a few. In my survey, although most pediatric ophthalmologists and certified orthoptists recommend some form of pencil push-ups, not one of the 35 surveyed practitioners limit their treatment to that alone.

·        Most examine patients at intervals of approximately 4 weeks, adding 1 or more of the aforementioned exercises to increase the intensity.

·        Of course, the duration (or ‘dose’) of any treatment program is also important.

·        Although the authors indicated that the pencil push-up exercise in their study averaged 15 minutes per day, I have trouble reconciling this with their prescribed program of 20 push-ups 3 times a day. It takes me 2 to 2.5 minutes to complete 20 pencil push-ups in the manner used by the authors. I suspect that the patients the authors assigned to pencil push-ups may in fact have only been exercising 6 to 7.5 minutes per day. All of the practitioners I surveyed recommend 3 to 5 times that duration.

·        Also, almost all I surveyed pointed out the importance of using a target that controls accommodation for pencil pushups, such as a letter or picture. Focusing on the tip of a pencil, as was done in this study, may result in the use of accommodative convergence to maintain a single image and would do little to improve fusional convergence [maybe Bates’ fusion exercises would have been more effective].

·        In short, the pencil push-up treatment program prescribed in this study is not representative of the standard of care of the ophthalmologic community. Given the low intensity of that program, I am not surprised the authors found it of no benefit.”

Archives of Ophthalmology (Journal): 'The Treatment of Convergence Insufficiency' by Burton J. Kushner, MD


Base-Out Prisms, Stereograms:

“Base-out prism reading and stereogram cards may be used by an orthoptist to improve fusional convergence.”

eMedicine - Convergence Insufficiency


·          Vision: Vision Therapy: 3D Stereo Images


Computer Programs:

“New, affordable computerized fusional vergence training programs (e.g., Computer Orthoptics) are available. These self-paced programs can be used on a personal computer at the patient's home.”

eMedicine - Convergence Insufficiency


Base-In Prisms

“Base-in prisms for near only: These prisms can be ground into a separate pair of reading glasses, or Fresnel membrane prisms can be fitted over the reading segment of the patient’s bifocals."

eMedicine - Convergence Insufficiency


Other Issues to be Considered

·          "Uncorrected high hypermetropia or myopia;

·          Early presbyopia…

·          Convergence insufficiency associated withaccommodative insufficiency: Patients with combined convergence and accommodative insufficiency are usually more symptomatic than those with convergence insufficiency alone. However, symptoms alone are not sufficient to distinguish between these 2 entities, and all patients who present with convergence insufficiency should have accommodative amplitudes checked since satisfactory treatment depends on a correct diagnosis.

·          Anticholinergic drugs, closed head trauma, and viral encephalopathies should be considered in the pathogenesis of this disorder.

·          In addition to treating the convergence weakness, plus lenses should be prescribed to these patients for reading.

·          Convergence paralysis…"

eMedicine - Convergence Insufficiency


Lack of Treatment

Untreated, the exophoria at near may break down to a poorly controlled intermittent exotropia. Fortunately, in most cases, convergence insufficiency is very amenable to orthoptic treatment."

eMedicine - Convergence Insufficiency


Psychological or Physiological?

"In the past, many ophthalmologists considered convergence insufficiency and its associated symptoms to be a neurotic manifestation of nonrelated psychologic problems best dealt with by a psychiatrist. However, it is now clear that convergence insufficiency is a legitimate, problematic binocular dysfunction. The clinician must consider whether the behavioral manifestations displayed by patients really result from the frustration caused by their inability to perform desired near visual tasks."

eMedicine - Convergence Insufficiency


Things to Avoid

While doing the pencil push-ups exercise it is important that you do not strain your eyes while looking at the pencil. Straining your eyes causes accommodative insufficiency. More information about accommodative insufficiency is included in the Causes section and on the Accommodative Insufficiency page.


·           Vision: 3D Stereo Images: Things to Avoid

·        Maximize the Effect of the Bates Method: Tips


More Definitions

More definitions for terms which may be found on the eMedicine - Convergence Insufficiency page


·        binocular diplopia

·        heterophoria

·        innervate

·        orthophoria

·        stereoscopic acuity


Convergence Insufficiency and ADHD

"'Convergence insufficiency may not be well known outside the field of eye care specialists,' Granet told Reuters Health. 'We don't know if children are being misdiagnosed with ADHD [attention-deficit/hyperactivity disorder] when they truly have convergence insufficiency or vice versa,' he said. 'We also don't know if one causes the other or if medications used for ADHD cause convergence insufficiency,' he added."

Eye disorder linked to ADHD in children


Things to Consider

Amblyopia Caused by Anisometropia

·          Vision: Binocular Functions: Amblyopia: Types: Amblyopia with Anisometropia


Related Topics

·          The Brain: Frontal Lobes: Effects: Pattern Recognition

·        Vision: Binocular Functions: Depth Perception



Back to 'Binocular Functions'