Strabismus (also known as an eye turn, wandering eye, crossed eye, or wall eye) is a lack of coordination between the eyes. This lack of neuromuscular control leads to double images. If not treated early, strabismus can lead to loss of vision or amblyopia (lazy eye) where the brain suppresses, or ignores one of the images to avoid seeing double. An eye turn can have the following effects:
- Poor coordination in sports when catching or throwing a ball
- Difficulty judging distances while driving and parallel parking, frequent fender benders
- Double vision
- Impaired depth perception
- Inability to see images truly “pop out” on 3D movies
- Dizziness or discomfort watching 3D movies
- Blurry vision
- Ghost images
- Difficulty reading
- Difficulty focusing on visual tasks
- Difficulty focusing on the person you are looking at, and when they are looking at you
- Crossed eyes can also have negative implications for a person’s self-confidence and social interactions.
- Burning – usually worse at end of day
- Excessive tearing or watery eyes
- Gritty feeling like sand in your eyes
- Vision clears up with blinking, but is blurry between blinks
- Vision is blurry towards end of day
- Symptoms are worse around fans or wind
- Red eyes
- Discomfort wearing contact lenses
- This can be accompanied by dry mouth or dry skin
- Frequent eye infections
Strabismus can result because of:
What do we do in a dry eye workup?
- improper development of eye muscle coordination in infants and children
- brain injury such as trauma, stroke or aneurysm that causes a paralysis of a nerve that controls the muscle
- problems with the nerves or muscles that control eye movement
- excessive farsightedness (hyperopia), or a large difference between the vision of each eye
- It is important to rule out any serious problem, such as a brain tumor that can be interfering with the nervous pathway in the brain that controls eye alignment. It is especially important if there is a new or sudden development of an eye turn.
Strabismus is classified by the direction that the “wandering eye” turns.
- Esotropia: eye turns in
- Exotropia: eye turns out
- Hypertropia: eye turns up
- Hypotropia: eye turns down
- Intermittent (i.e. when tired or after prolonged reading or computer use)
- Alternating (between right and left eye turn)
Pseudo-strabismus, a fake strabismus, can occur in newborns. A child’s eyes may drift in and out of alignment because he has not developed bilateral integration or coordination of his eyes. The eyes usually straighten as the infant’s visual system develops. Infants also often have a wide, flat nasal bridge and a fold of skin at the inner eyelid that tends to hide the eye when looking to the side, thus creating the illusion that the eyes are turned inwards. A Developmental Optometrist can easily distinguish a true strabismus from a pseudo-strabismus.
Early treatment for strabismus, is very effective, especially if one of the reasons that the eyes turn inwards is due to a high amount of hyperopia or farsightedness. If not treated early, this can result in an eye turn inwards, called Accommodative Esotropia by age 2-3 years old. This occurs because when eyes are under powered, as in hyperopia, they converge when focusing. At first, the eye turn is intermittent, but may become constant when left untreated.
Professional and Olympic athletes usually have better visual skills than the average person, but at a highly competitive level, superior visual skills make a difference. When I evaluated athletes at the 1996 Summer Olympic Games in Atlanta, Georgia, I was impressed that other countries also train their athletes to improve visual skills such as tracking, focusing and eye muscle coordination. Even sports such as diving and boxing use Vision Therapy to help their athletes’ sight targets more accurately, and to react more quickly to a visual stimulus.
I was proud that the Sports Vision Training equipment and techniques that we use in the United States are more advanced than most other countries. The Sports Vision Training that I used with the Mighty Ducks of Anaheim hockey players is also used by the U.S. Olympic athletes who train in Colorado Springs, as well as by many professional franchises in the NBA, NHL, NFL and MLB.
Types of Strabismus (Dreamstime.com)
Strabismus is one of the reasons that the American Optometric Association recommends a child’s first vision exam is given at 6 months old, and yearly thereafter. Another important reason to begin annual vision exams during infancy, is that it is nearly impossible for parents to know whether their child’s vision is normal, whether the eyes are tracking or teaming correctly, and it is impossible for a child to know what “normal” looks like; therefore, she would not know to tell her parents that she does not see correctly.
The goals of treatment for strabismus are restoring 3-dimensional vision, functional vision, eye alignment, and restoring vision to the eye that is misaligned. Treatment options for strabismus include:
- Vision Therapy
- Eye muscle surgery
- Glasses which may incorporate prism
Vision Therapy may be necessary after eye muscle surgery to restore full visual function such as depth perception.
Vision Therapy is an individually customized type of physical therapy program for the eyes to train eye muscle control and coordination. Vision Therapy also works on stimulating the visual system to function normally. Vision Therapy sessions include procedures designed to enhance the brain’s ability to control:
- eye alignment
- eye teaming
- eye focusing abilities
- eye movements
- visual processing
Eye surgery – by Banol2007 on Dreamstime.com
Visual-motor skills and endurance are developed through the use of specialized computer and optical devices, including therapeutic lenses, prisms, and filters. During the final stages of therapy, the patient’s newly acquired visual skills are reinforced and made automatic through repetition and by integration with motor and cognitive skills.
While vision therapy includes the eye muscle training methods of orthoptics, it has advanced far beyond it to include training and rehabilitation of the eye-brain connections involved in vision. Clinical and research developments in vision therapy were closely allied with developments in neuroscience during the twentieth century. Research continues in the 21st century.
In vision therapy programs, optometrists look at the neurological control system to treat the whole visual-motor system and alter reflexive behavior, which results in a lasting cure. Vision Therapy for strabismus generally consists of either weekly or bi-weekly office based therapy under the supervision of a Vision Therapist and Developmental Optometrist to make sure the procedures are accurately performed and progress is monitored. We also prescribe home therapy to reinforce in-office therapy and accelerate treatment.
If you have any questions about Strabismus or Vision Therapy, please call our office at (323) 954-5800.
Copyright Hollywood Vision Center – Optometry 2013