Dynamic visual acuity - is the ability to stay focused on fast-moving objects. This has nothing to do with generally good eyesight, as even people with perfect static vision aren't guaranteed good dynamic acuity. Many people aren't aware of the fact that visual observation from a static position differs greatly from that of a moving position. Whether it is you or the objects that are in motion is less important to this equation. Sitting still while reading something from a paper that doesn't move is incomparable to that of sitting still and watching motion in play. There are several ways in which you test this out for yourself at home. A simple method is by creating a mobile that can be hung from the ceiling or a turntable that can be stood on a desk. Cut out different size letters from a newspaper or magazine and then stick these on the various planes of the mobile. As it revolves, see if you can focus on each individual letter as it flashes past you. If you choose to see a specialist, they will examine your ability using a computer program that displays an array of objects or letters moving across the screen. The speed of the moving objects slowly picks up pace and focusing on each becomes more and more difficult. In sports the athletes that need this ability most are skiers and road cyclists, who constantly have to keep tracking of their surroundings as they speed past it- and through it.
Focus flexibility - refers to a person's ability to switch focus from a nearby object to one farther away. This is obviously vital to sports where many people and objects keep moving across your field of vision, coming closer and then quickly getting farther away. A home-method for exercising this ability is to focus intensely on something inside the house and then switching quickly to a scene outside the window. Holding you gaze for a few seconds and then changing it forces your eyes to re-align and this exercises the internal eye muscles responsible for this skill. If you have any misgivings about having a problem with this ability, your eye-care practitioner can easily test this with a simple hologram display.
Color Vision - is our ability to differentiate between the various ranges of light that ultimately create color. Color blindness or impaired color vision is usually a man's problem and very few women are known to suffer from it. Being able to distinguish between an object of one color on the background of a second color is not a perfect ability in most people, but the combination of red and green is known to be the most difficult to distinguish. This is apparent in televised games such as football, where the playing field is bright green and the ball has a reddish-brown color. A simple way to test this is to view cards printed with spots of one color on a differently-colored background. There are also special glasses and contact lenses for people with acute color blindness, though not many eye-doctors supply them and they are far less available than other specialized lenses. They are specifically designed to augment color contrasts. In sports color augmentation has become almost commonplace these days. In such games as tennis or basketball, where the ball is yellow or orange, there are now contact lenses and glasses that enhance yellow by filtering out other, less important, colors. This focuses the players ability to see and track the ball, especially at high speeds.
Peripheral vision or peripheral awareness- is the ability to see your surroundings without moving your head, and using only your eyes. Every person has a limit to his/her peripheral vision and most are in the same general range, but there are ways in which you can improve your peripheral range. A specialist tests this parameter by asking you to look straight forward at a certain image while flashing other images at you from side angles. If you would like to practice this at home- stare at the television at home while sitting as a sideway angle from the screen. Then attempt to describe what's happening on the screen simply by what you see from the corner of your eye. A perfect ninety degree angle is the best test for this sort of thing.