• Comprehension reduces as reading continued: loses interest too quickly
• Mispronounces similar words as continues reading
• Blinks excessively at desk tasks and/or reading; not elsewhere
• Holds book too closely: face too close to desk surface
• Avoids all possible near-centered tasks
• Complains of discomfort in tasks that demand visual interpretation
• Closes or covers one eye when reading or doing desk work
• Makes errors in copying from chalkboard to paper on desk
• Makes errors in copying from reference book to notebook
• Squints to see chalkboard, or requests to move nearer
• Rubs eyes during or after short periods of visual activity
• Fatigues easily; blinks to make chalkboard clear up after desk task

Accommodative Insufficiency

Accommodative insufficiency occurs because of the eye can not maintain clear vision at near.

Ill-Sustained Accommodation

Ill-sustained accommodation is similar to accommodative insufficiency except print may initially appear clear and easy to read without effort.  With time, the task at near begins to require more effort to focus.  Blurred vision, eyestrain and headaches can occur with sustained effort.  A simple visual acuity test at near (as what is frequently done during a vision screening) will usually not detect this problem.

Normal Focusing

Our focusing system is usually quite fast at focusing.  Most people can focus at near in about 1/5 of a second as simulated above.

Accommodative Infacility

With accommodative infacility, there is a delay in the clearing of the print.  The simulation above shows how a student with this problem would be slowed.  Copying information from a chalkboard to your desk is a frequent activity in a classroom.  It takes the student longer to obtain and transfer the information.

For all of the above problems, lenses or vision therapy or a combination of both may be prescribed.  The success of treatment is quite high.  A few cases may require only short term use of lenses or vision therapy while others may have a need throughout their youth for this type of help.

Convergence Insufficiency can produce visual symptoms which also include blurred vision, double-vision, or jumbling and scrambled print as you try to read.

Causes

Convergence insufficiency occurs because of poor eye-teaming ability.  Initially when we view something up close the lines-of-sight from each eye should cross directly where we look at.  A tendency for the eyes to want to drift outward is present in individuals with this disorder.  In order to to keep the image clear and single, more effort is required in order to concentrate on the task.  This ever increasing effort is taxing and soon results in symptoms.  This disorder can run in some families.

Symptoms

Blurred vision at near, eyestrain while doing near work, headaches, sleepiness while reading, double-vision, frequent loss of place when reading,  inaccuracy while checking columns of figures or lists are common complaints.  Severe cases can result in an eye turn.

Diagnosis

A complete and thorough vision exam is required in order to detect this disorder.  During this exam tests must be performed at a near distance in order to measure the eyes tendency to drift and how much ability the eyes have to compensate for this effect.  If not performed this disorder can be missed by the doctor.

Treatment

1. Vision therapy is by and far the most successful treatment available for convergence insufficiency.  The goal of therapy is to build eye teaming ability to a level necessary to overcome the outward drift tendency.

2. Prism incorporated into an eyeglass prescription is a second option.  Success with this form of treatment is much limited than with vision therapy.  Very often adaptation to the new prescription occurs and the convergence insufficiency returns.

3. Alternatives include ocular muscle surgery however most experts do not support this mode of treatment today except in unusual cases.

Video on Convergence Insufficiency

This video reports on results from a study by the National Institutes of Health / National Eye Institute on the treatment of convergence insufficiency.

Cataract Surgery is Done with Lasers
Never – almost. Yes, experimental research but nothing practical yet developed. Nearly 100% of cataract surgeries are still performed with traditional microsurgical techniques. Lasers can be used after cataract surgery to clear up cloudy membranes. This is where the confusion may often lie.

All Red Eyes are Infections
It has been our experience in our office that most red eyes are due to allergies or dry eye.We see more viral than bacterial etiological causes. This is why your eye doctor can’t just call in some antibiotic. Antibiotics fight bacteria and do not kill viri or decrease allergies.

Refractive Surgery Forever Removes the Need for Eyeglasses
People may assume no more visits are required to the eye doctor after refractive surgery. In fact people need MORE FREQUENT eye care after eye surgery. Refractive surgery today has a better than ever chance of eliminating your refractive error. One condition it can not cure however is Presbyopia. Presbyopia is the natural loss of focusing ability which first shows symptoms past the age of 40. Increasing working distance, eyestrain, blurred near vision are its symptoms. Presbyopia is not treatable except for corrective lenses.

Contact Lenses can be Welded to the Eye if you Weld with Them In
Nope. Contact lenses actually have been found to protect the eye from severe injury. Less trauma has been observed following foreign bodies and chemical splash/burns to the eye. A contact lens has been found to act as a protective shield for the cornea often taking the brunt of damage.

Stronger Glasses can Fix Every Vision Problem
“All I need is a pair of glasses that will work.” is a complaint often heard by eye doctors from patients seeking second opinions due to eye and vision conditions which have deteriorated their ability to see. Neurological problems can interfere with vision. Post-concussion syndrome frequently complicates vision problems. Cataracts interfere with a person’s ability to see. Retinal diseases like macular degeneration often cause a desire for a patient to ask the doctor for stronger glasses. Sometimes they are prescribed, but often special low vision magnifiers, electronic magnification aids and other special aids are needed.

Poor Night Vision is Infrequent
This is actually our most common complaint that we hear of. Small refractive errors is #1 cause. At night the pupil dilates which causes the eye to become more sensitive to changes in an eyewear prescription. Cataracts, macular degeneration, optic nerve disease and contact lens overwear can decrease night vision as well. Nicotine has been shown to decrease the ability to dark adapt. Dirty car windshields can create a phenonema known as the Mandelbaum effect. The focusing system draws inward creating an artificial form of near-sightedness. Night myopia is a similar phenonema which can occur as well despite perfectly clear windshields. Rainy weather decreases your ability to see to drive at night. Wet roads decrease the amount of light reflected back to you from your headlights and increase the amount of light from oncoming cars. Often no detectable problems are found. Aging is a frequent cause of night vision problems. The retina takes longer to recharge its photoreceptor chemicals as we mature. Retintitis Pigmentosa, a traditional cause of night blindness is another retinal disorder which has classically been associated with poor night vision is actually very uncommon.

Eyeballs are Removed During Surgery
Rarely, surgeons usually work around them. The muscles and the optic nerve are of a fixed length. Removing the eye risks avulsing (tearing) of the optic nerve.

“I’m Legally Blind Without my Glasses”
By it’s definition legal blindness is 20/200 in the better eye with correction (glasses or contact lenses) or less than a 20 degree visual field in the better eye. To say you are legally blind without glasses is not in keeping with the true definition.

These Lenses are Scratch-Proof
No lens yet developed is truly scratch-proof. There is always some material which can scratch a lens. A diamond can be scratched by another diamond. Lenses instead should be termed scratch-resistant. A plastic lens with a scratch-resistant lens is more durable than a lens without the coating. Glass to this date remains the most scratch-resistant material – more durable than plastic with a scratch-resistant coating.

Amblyopia is a condition of underdeveloped vision.  Findings of underdeveloped vision can be considered a constellation (grouping) of findings that include lowered visual acuity, decreased accuracy and ability of ocular movements such as pursuits (slow eye movements) and saccades (fast eye movements), decreased focusing abilities and decreased visual processing skills.   Decreases in stereopsis (3D vision / depth perception) and restrictions in visual field (tunnel vision) can be measured clinically.   Most cases develop as a result of an eye turn (strabismus) or undercorrected refractive error.  Amblyopia can occur in 2.5% of the population, making it responsible for more loss of vision than all ocular diseases and trauma combined.

Streff syndrome is a different type of amblyopia labeled psychogenic.  This type is under-reported in the medical literature.  Psychogenic means the origin is in the mind or more accurately in the parts of the brain that process vision.  Psychogenic amblyopia can involve voluntary and involuntary types.  Voluntary psychogenic amblyopia is also known as malingering – a process of faking a condition for some type of gain.  Involuntary psychogenic amblyopia involves vision and vision processing problems that occur in a patient who is not malingering.  Their problem is real, measurable and not being faked for some type of gain or attention.  There is no organic base for the problem meaning that there are no observed structural or anatomic anomaly that can account for the problem.  Saying that a problem is not organic however does not account for possible genetic, biochemical, electrophysiological or other abnormalities that may be present but for which we do not have the technology or background to identify them.  The word functional means that the normal expected work or function that a process is supposed to offer (such as correct focusing) does not occur.

Streff syndrome is believed to develop as a result of stress.  Hans Selye classifies stress as eustress – stress affiliated with change for the better such as marriage, getting an A on a test, being accepted into college or distress – stress affiliated with change for the worse such as divorce, family problems, substance abuse, emotional abuse, health problems.  A reaction from too much stress can include behaviors that trigger a person’s alarm mode especially if there is to0 much stress leading to an overload.

A diagnostic pattern has been described for patients susceptible to Streff syndrome.

• Prepubescent or early pubescent ages 10 – 14
• Females more frequent than males
• Visual acuity worse than 20/20 to  20/200
• Visual skills problems in ocular movements, ocular focusing, visual information processing.

Symptoms noticed by patients, parents and teachers can include:  a sudden decrease in academic performance, lack of desire to pursue homework, increased errors on homework, blurred vision at distance and at near, blurred vision of varying amounts which can come and go but usually stay blurry and headaches.

Sometimes the eye care professional can elicit a recent history of family stress, social stress, recent relocation.

The main clinical treatment of this condition is the use of a low plus eyewear prescription.  This may be in the form of reading glasses or a multifocal.  The effect of this prescription reduces the visual stress by just enough to allow the visual system to re-engage, organize and process information efficiently.  Results are usually quickly obtained with improvements seen within a few weeks.    Some cases may require vision therapy to improve eye movements and focusing.   In cases unresponsive, eye care professionals should always rule out organic pathology both at the time of the initial diagnosis and later on.

In 1962, Dr John Streff first published a description of this condition.  Articles in the optometric literature are more numerous than ophthalmological literature.  This condition needs more research.  The condition is considered functional in nature.  Functional means no organic pathology exists but the software programming of the visual system is inefficient or not working as it should.

More Information:  Streff Syndrome.pdf
(an information pamphlet written by Paul Harris, OD on this condition)

Much of this information is adapted from: Press, Leonard. Applied Concepts in Vision Therapy, St. Louis:  Mosby 1997

Cook, Douglas T & Maples, WC. NSUOCO Vision Therapy Pocket Reference, Tahlequah:  SITE 1994