Eye coordination is the ability of both eyes to work together simultaneously and accurately as a team. This synchronized action allows the visual system to direct gaze toward the same point in space, which is necessary for clear, comfortable vision. When the eyes are coordinated, the brain receives two slightly different images that it can easily process, forming the basis for perceiving the three-dimensional world.
What Coordinated Vision Means
The goal of coordinated vision is to achieve binocular vision, using both eyes together to form a single, unified image. Because the eyes are spaced approximately 6.5 centimeters apart, each eye captures a slightly different perspective of the same object, creating retinal disparity. The brain receives these two distinct two-dimensional images and combines them into one cohesive picture. This fusion process enables stereopsis, or true depth perception, which provides the judgment of distance and spatial relationships necessary for navigating complex environments. Without this precise coordination, the brain may struggle to merge the images, leading to visual discomfort or the suppression of one eye’s input.
The Muscular and Neurological Mechanics
The physical movements required for eye coordination are executed by six small extraocular muscles attached to the outside of each eyeball. These muscles work in synergistic pairs to move the eye up, down, left, right, and rotationally. For the eyes to work as a team, the brain must send precise, coordinated signals to the muscles of both eyes simultaneously.
Three main types of movement are required for full coordination. Saccades are rapid movements that quickly shift the gaze from one target to another, such as when reading a line of text. Pursuit movements are slower, smooth motions that allow the eyes to track a moving object. Vergence movements involve the eyes turning in opposite directions—inward (convergence) for near objects, or outward (divergence) for far objects—to maintain focus at varying distances.
Common Coordination Disorders
When the muscular and neurological mechanics fail to coordinate effectively, several disorders can occur. Strabismus, often called crossed eyes or an eye turn, is a condition where the eyes are visibly misaligned and do not point at the same object simultaneously. This misalignment can manifest as the eye turning inward (esotropia), outward (exotropia), or vertically (hypertropia or hypotropia).
Convergence Insufficiency is a specific difficulty in turning the eyes inward to focus on near objects like a book or computer screen. This failure to maintain proper alignment during close work often leads to symptoms like double vision, eye strain, and headaches. If a coordination issue like strabismus is present from a young age, the brain may begin to ignore the visual input from the misaligned eye to avoid seeing double. This sensory suppression can lead to the development of Amblyopia, or “lazy eye,” where visual acuity decreases in the suppressed eye even when corrected with lenses. Amblyopia is a functional problem where the brain pathways for vision from that eye fail to develop correctly.
Diagnosis and Non-Surgical Improvement
Eye care professionals diagnose coordination problems using specialized assessments. A common diagnostic tool is the cover test, where the examiner observes the movement of one eye while the other is briefly covered, revealing any tendency for the eyes to drift out of alignment. Vergence testing measures the limits of the eyes’ ability to converge and diverge, often by measuring the near point of convergence—the closest point an object can be while maintaining single vision.
Many eye coordination issues respond well to non-surgical interventions, with Vision Therapy being a frequent treatment approach. Vision Therapy involves a personalized program of exercises designed to train the eyes and the brain to work together more efficiently. These exercises improve control over the eye muscles and strengthen the neurological pathways responsible for visual skill development. Corrective lenses, especially those incorporating prisms, are also used to manage certain coordination issues. Prisms work by bending light before it enters the eye, shifting the image so the eyes do not have to strain to achieve a single, comfortable image.