OptoDrum is an easy to use replacement for a bulky optokinetic drum or a fraying cloth tape to elicit optokinetic nystagmus for evaluation of neurological, otological, and opthalmological disorders. Simply place the iPhone with a moving pattern in front of a patient’s eye to elicit the response. The stripe pattern, width, and speed are easily adjustable. • OptoDrum provides five patterns: black stripes, red stripes, mixed colors, symbols, and animals. • Drag a finger up or down the screen to make the pattern move at the speed of your finger. • Double tap the moving pattern to make it stop. • Pinch or zoom the pattern with two fingers to narrow or widen the pattern. • A left or right finger swipe switches a stopped pattern to the next one in rotation.