Normally, both eyes work together to look at something. Sometimes, however, the eyes do not align with one another. This condition is called strabismus, or crossed eyes. For people with strabismus, one of their eyes might turn inward, outward, upward, or downward, while the other eye appears normal. Because the eyes are looking at two places, the brain receives very different images from each eye. This results first in double vision, and then a gradual reduction of vision in one eye as the brain learns to ignore the disparate images.
With normal vision, the two eyes focus on a single spot, sending the brain two images which the brain combines into one. When eyes fail to work together as a team, pointing to two spots near one another instead of a single spot, the brain receives images that are too different from one another; instead of fusing the images, the brain registers the two images separately resulting in double vision. This is called convergence insufficiency.
When reading, our eyes fixate briefly on a word while, peripherally, we keep track of where we’re looking. People who have tracking problems cannot read seamlessly. Their eyes jump around when looking at something close-range, leading to a dislike for reading, among other things.
In order to see clearly when looking at a distance as well as close-up, the eye accommodates, focusing the eye appropriately. The inability to focus the eye as needed blurs images, oftentimes causing headaches.
Visual Perceptual Processing
Visual perceptual processing, or visual information processing, involves integrating information from your surroundings with your other senses, and is integral to everything from understanding directions to riding a bike. Perceptual skills include visual-spatial skills and visual analysis skills.
Visual Motor Integration
Colloquially known as eye-hand coordination, visual motor integration is the ability to control your hand movements in response to what you’re seeing. A lack of proper integration negatively affects a wide range of activities.
The ability to remember what you are seeing is crucial, especially for reading purposes. Those with poor visual memory might forget what they just read or even forget what a word looks like.
Visual processing refers to the ability to analyze and interpret visual information.
Processing speed is the ability to process visual information quickly and accurately.