Excalibur Einstein Eye Trainer ET450 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.