EXCALIBUR ET450 Einstein Eye Trainer. Think you have a quick eye. Pick up the included stylus and test your visual acuity. Compete against yourself or a friend. Keep yourself sharp with this pocket-size, touch-screen eye trainer you can take with you anywhere. You can use it while waiting in line, carpooling to work, or while on a break. Spend a few minutes sharpening one of your most important assets, your vision. Five training modes- Dynamic Training, Panorama Training, Snap Training, Eye-Hand Training and Eye Gym. Each mode has two games. You can also have fun training your eyes with specially designed games: Simon-Gym, Sequence, Eye Gym, Magic Hand, Rectangle Finding, Snap and Counting, Quick Touch, and Snap. Progress in each game as it becomes more and more difficult. Requires two AG13 batteries, included.