The Cause of Internet and TV Addiction?
"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
· Blurred vision, or
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 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."
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."
Most Common Symptoms
"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.
"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.)."
"Symptoms are aggravated by illness, lack of sleep, anxiety, and prolonged near work."
"The frequency of symptoms may increase with age as patients' ability to compensate for their relative divergent binocular alignment decreases with time. "
"The causes of convergence insufficiency are not completely clear. A connection has been made between accommodative insufficiency and 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."
"This [eyestrain] most commonly occurs due to the sustained increased effort required to increase fusional convergence."
"…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."
"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."
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:
http://www.appleblossomart.net/Cursors/Science-Cursor-Library-Cursors.htm (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)
· Newsgroup: microsoft.public.windowsxp.general: 'Old 9x Themes in XP' (for Windows XP users)
· Vision: Bates Method: Palming (for fatigue)
"Convergence exercises (orthoptic therapy) and/or base-in prisms are the mainstays of treatment for convergence insufficiency.”
Note: Please read the section Things to Avoid before trying these 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.”
“As previously mentioned, this condition is thought to be due to a relative imbalance in eye muscle strength.”
“Adding a small base-out prism in front of one eye may increase the intensity of the exercise."
· “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.”
“Base-out prism reading and stereogram cards may be used by an orthoptist to improve fusional convergence.”
“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.”
“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."
· "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…"
"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."
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.
More definitions for terms which may be found on the eMedicine - Convergence Insufficiency page
"'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."
Amblyopia Caused by Anisometropia