With the 7 Visual Abilities:
1. 20/20 Eyesight
The first and best known visual ability is 20/20 eyesight. If, at twenty feet, you can see the same letters that people with normal eyes can see at twenty feet, then we say that you have "20/20 eyesight."
Unfortunately, 20/20 eyesight—with or without new glasses—does not mean that during reading and desk work you can see clearly for more than a few minutes. 20/20 eyesight doesn't mean that you have the depth perception and localization skills to drive at night or that you are free from vision-caused headaches and general fatigue. All 20/20 eyesight guarantees is that you can see clearly long enough to call out six letters on a doctor's eye chart. Therefore, in addition to "20/20 eyesight" we have to consider 6 other visual abilities that are generally ignored during routine exams.
2. Eye-Muscle Coordination
The second visual ability is Eye-Muscle Coordination. We have fourteen eye muscles. The brain must coordinate these muscles perfectly if we are to see comfortably and efficiently. If this coordination is difficult, eyesight may be clear at times but blurred or double at others. The effort to prevent such blurred or double vision (diplopia) can cause premature fatigue, or loss of attention and comprehension during reading, desk or computer work. Certain types of eye muscle coordination problems can reduce depth perception (3D Vision) for driving and sports. In extreme cases, poor eye muscle coordination can even cause crossed or lazy eyes (strabismus or amblyopia).
3. Eye Control:
Eye Control is used for "keeping our eyes on the ball" or maintaining eye contact during conversations. When Eye Control is inaccurate, seeing is inaccurate. Our Eye Control is a direct measure of how vision is affecting our attention.
4. Visual Tracking
We use the term Visual Tracking to include how quickly and accurately we move our eyes across a line of print. During reading, poor Visual Tracking causes loss of place, confusing one word with another, careless errors, and difficulty breaking words down into their parts.
5. Visual Perception
"Visual Perception" is the ability to see how things are alike and different, how the pieces fit together to make up the whole. At one extreme we have the artist who can look at a scene and "see" the relationships between the shapes and colors well enough to reproduce them with paint on canvas. On the other extreme, we have the child who cannot tell the difference between a "b" and a "d" or a "was" and a "saw". Visual perception problems can make it difficult to recognize words, complete puzzles, align columns in math or—for adults—read a roadmap.
6. Eye-hand Coordination
We can divide our ability to get our eyes to guide our hands into "little" coordination and "big" coordination. We need "little" coordination to copy sentences and to keep words equally spaced and on the line. We need "big" coordination to throw or catch a ball or to guide a steering wheel. The "big" type of eye-hand coordination is also very much linked with balance, general coordination, and 3D Vision.
Visualization is sometimes called, "seeing with the mind's eye." If visualization is good, a child or adult can "see" words in the mind to spell them. They can "see" the story when they are reading. They can picture their goals in their minds. They have the ability to picture the consequences of their actions. Visualization allows us to learn from the past and plan for the future.