Eye Tracking Problems
- Convergence insufficiency means the eyes do not turn inward accurately when focusing on a nearby object. When reading or looking at a close object, the eyes should come together to focus. This binocular vision results in a single figure being seen. With convergence insufficiency, a person can't move the eyes inward to normally focus. Older children and teenagers are most often diagnosed with convergence insufficiency. Often, parents confuse this condition for a learning disability, because it produces reading problems. Normally, learning disabilities are not caused by convergence insufficiency. Common symptoms associated with convergence insufficiency are headaches, eyestrain, difficulty reading, double vision, sleepiness, a pulling sensation around the eyes, trouble concentrating and squinting, and closing or rubbing one eye.
- Esophoria is an extra-ocular muscle discrepancy in which both eyes are open and each points precisely at the appointed target. When one is covered, that eye turns inward. Esophoria is also called over-convergence.
- Esotropia occurs when the eyes are open and one of them turns inward. It can be constant or intermittent. Each category of esotropia requires its own treatment or therapy. Congenital esotropia means from birth. During the first three months of life most infants' eyes slowly come into a more dependable alignment as synchronization develops. Infantile esoptropia occurs when a baby uses the right eye to look left and the left eye to look to the right. Accomodative esotropia is usually noted around age 2; it means excessive inward turning of the eye.
- Exophoria occurs when one eye or both have a tendency to drift outward; it is a form of strabismus. When both eyes are open they will focus accurately at the appointed target, but when one eye is covered the other one will turn outward. Exophoria is also called under-convergence. It is typically caused by nerve, muscle or congenital problems or mechanical anomalies. Exophoria is common in childhood and infancy and might increase with age.
- Exotropia is a muscle condition in which one eye turns outward when both eyes are open. If the outward turn occurs 100 percent of the time it is called constant, otherwise it is called intermittent. Crossed diplopia, or double vision, is often experienced by people who have exotropia. Types of exotropia include sensory exotropia, infantile exotropia and essential exotropia.
