Frequently Asked Questions
- What Is Vision Therapy?
- What Is Amblyopia (Lazy Eye)?
- Are Lazy Eye And Strabismus The Same?
- What Causes Amblyopia?
- How Do You Diagnose Amblyopia?
- When Should Amblyopia Be Treated?
What Is Vision Therapy?
Optometric vision therapy is an individualized treatment regimen prescribed for a patient in order to:
- Provide medically necessary treatment for diagnosed visual dysfunctions
- Prevent the development of visual problems
- Enhance visual performance to meet defined needs of the patient
Optometric vision therapy is appropriate treatment for visual conditions which include, but are not limited to:
- Strabismic and non-strabismic binocular dysfunctions (crossed eyes)
- Amblyopia (lazy eye)
- Accommodative dysfunctions (eye focusing)
- Ocular motor dysfunctions
- Visual motor disorders (handwriting)
- Visual information processing disorders
The systematic use of lenses, prisms, filters, occlusion and other appropriate materials, modalities, equipment and procedures is integral to optometric vision therapy. The goals of the prescribed treatment regimen are to alleviate the signs and symptoms, achieve desired visual outcomes, meet the patient’s needs and improve the patient’s quality of life.
Approved by the American Optometric Association Board of Trustees
November 1996
What Is Amblyopia (Lazy Eye)?
Amblyopia, commonly known as lazy eye, is the eye condition noted by reduced vision not correctable by glasses or contact lenses and is not due to any eye disease. The brain does not fully acknowledge the images seen by the amblyopic eye. This generally affects only one eye but may manifest with reduction of vision in both eyes. It is estimated that three percent of children under six have some form of amblyopia. [Return to FAQ Menu]
Are Lazy Eye And Strabismus The Same?
Many people believe that a person who has a crossed or turned eye (strabismus) has a “lazy eye,” but lazy eye (amblyopia) and strabismus are not the same condition. Some of the confusion may be due to the fact that strabismus can cause amblyopia. Amblyopia can result from a constant unilateral strabismus (i.e., either the right or left eye turns all of the time). Alternating or intermittent strabismus (an eye turn which occurs only some of the time) rarely causes amblyopia.
A turned eye (strabismus) may be easily spotted by a lay person but amblyopia without strabismus or associated with a small deviation usually cannot be noticed by either you or your pediatrician. Only an eye doctor comfortable in examining young children and infants can detect this type of amblyopia. This is why early infant and pre-school eye examinations are so necessary.
Due to misunderstanding or misuse of the terms for different visual conditions (i.e., crossed eyes vs. lazy eye), many people are inaccurately labeled as having a “lazy eye.” If you think you or someone you know has a lazy eye, it is recommended that you learn more about different types of strabismus, such as Exotropia (eye turns outward) or Esotropia (eye turns inward). [Return to FAQ Menu]
What Causes Amblyopia?
The two eyes must receive clear images during the critical period. Anything that interferes with clear vision in either eye during the critical period (birth to 6 years of age) can result in amblyopia (a reduction in vision not corrected by glasses or elimination of an eye turn). The most common causes of amblyopia are constant strabismus (constant turn of one eye), anisometropia (different vision/prescriptions in each eye), and/or blockage of an eye due to trauma, lid droop, etc. If one eye sees clearly and the other sees a blur, the good eye and brain will inhibit (block, suppress, ignore) the eye with the blur. Thus, amblyopia is a neurologically active process. The inhibition process (suppression) can result in a permanent decrease in the vision in that eye that can not be corrected with glasses, lenses, or surgery. [Return to FAQ Menu]
How Do You Diagnose Amblyopia?
Since amblyopia usually occurs in one eye only, many parents and children may be unaware of the condition. Far too many parents fail to take their infants and toddlers in for an early comprehensive vision examination and many children go undiagnosed until they have their eyes examined at the eye doctor’s office at a later age.
The most important diagnostic tools are the special visual acuity tests other than the standard 20/20 letter charts currently used by schools, pediatricians and eye doctors. Examination with cycloplegic drops can be necessary to detect this condition in the young. [Return to FAQ Menu]
When Should Amblyopia Be Treated?
The answer is as soon as it is diagnosed. Amblyopia can be successfully treated up to the age of 17. See a report on the latest research at National Institutes of Health — National Eye Institute. Early treatment is usually simple, employing glasses, drops, vision therapy and/or patching. Detection and correction before the age of two offers the best chance for a complete cure.
According to current research, amblyopia can not be cured — normal 20/20 stereo vision — without early detection and treatment. However, treatment for older children and adults is usually successful in improving vision and should be attempted. Treatment of amblyopia after the age of 17 is not dependent upon age but requires more effort including vision therapy. Every amblyopic patient deserves an attempt at treatment.
Strabismus is responsive to treatments at all ages. Therefore, as explained earlier, it is important to make careful distinction between amblyopia and strabismus. [Return to FAQ Menu]