Eye Turns, Crossed Eyes, Lazy Eyes
Strabismus is commonly referred to as a crossed eye or wandering eye. It is a visual condition in which a person’s eyes do not point at the same object at the same time. The result is the appearance of one eye turning in relationship to the other. The eye turn may occur constantly or only intermittently. Eye-turning may change from one eye to the other, and may only appear when a person is tired or has done a lot of reading.
A person with strabismus has reduced binocular function and depth perception. People who have strabismus struggle with visual space orientation, meaning the conflicting information about where the eyes are looking causes the person to be unsure of where they are in relation to other people and objects in space. This orientation is a mental phenomenon that exists in the visual cortex of the brain.
Strabismus is a manifestation of a whole-body problem! Researchers have found that improvements in gross motor and fine motor skills that are part of a Vision Therapy program contribute to improvements in a patient's ability to control their strabismus.
If left untreated, the eye that turns may develop reduced visual acuity, a condition known as amblyopia, or lazy eye. Whether the eye turn is constant or intermittent, strabismus always requires treatment. It will not go away on its own and children will not outgrow it.
A holistic approach to treating strabismus is validated by research studies. For example, an important study appeared in the May 2014 issue of the journal Vision Research which investigated how the information from eye-muscles muscles affects postural stability in adults with binocular vision disorders and demonstrated that those with binocular vision disorders showed significantly worse balance control than those without binocular vision disorder, even when they were only using only one eye.
The study showed that inaccurate signals related to the eye muscles have an impact body balance and that this effect can last into adulthood even where subjects had surgery as children to make the eyes appear straight.
The study also shows that specific therapeutic tasks (i.e. vision therapy) can allow patients with strabismus to develop better body balance.
Here is a passage form a commentary by Dr. Leonard J Press OD, FAAO, FCOVD and Dr. Joseph D Napolitano MD on why this research is so exiting:
Why is this research exciting? It counteracts the notion that strabismus is an isolated eye muscle problem that has little bearing other than cosmesis. The appearance of the eyes is only one feature of strabismus, better appreciated as a difficulty in multimodal coordination. This presents new opportunities to conceive of the synergy between extra-ocular muscle (EOM) surgery and optometric vision therapy, somewhat analogous to the synergy between orthopedic surgery and physical therapy.
When conceived in this fashion, the cognitive and attentional resources employed in optometric vision therapy help the brain to coordinate both eyes through activities mediated through the cerebellum. Even when [eye muscle] surgery or optometric vision therapy do not achieve bi-foveal alignment or random dot stereopsis, very meaningful gains can be realized in improved head to toe motor control.
The role of vision therapy features prominently in this study. Here is what the authors say:
Sources: Impaired Body Balance Control in Adults With Strabismus Vision Res 2014 May 01;98(-)35-45, A Przekoracka-Krawczyk, P Nawrot, M Czaińska, KP Michalak
Amblyopia is commonly referred to as lazy eye. It is a visual condition that is marked by reduced vision, which is not correctable by wearing glasses or contact lenses. Amblyopia is often the result of long-term suppression of the eye’s signal from the brain. The treatment of strabismus and amblyopia are quite similar. While historically it was felt that nothing could be done about amblyopia after the age of seven, new research and clinical experience have shown that strabismus and amblyopia can be treated successfully at any age. The tradition of patching the “good eye” has fallen out of favor as research demonstrates that constant patching can damage the binocular cells of the eye. Newer treatment methods utilize minimal patching combined with appropriate activities that stimulate both the monocular and binocular cells of the eye.
It is important to note that amblyopia can be present when there is no physical problem with the eye itself. Disease or injury are just a few of the possible causes of amblyopia. There are many reasons why a person may develop amblyopia. It is important that a doctor determine the cause and provide the appropriate treatment.