Replace your bulky optokinetic drum with OKNDrum. OKNDrum is the easy-to-use alternative to a physical optokinetic drum. Our app is used to evaluate neurological, otological, and ophthalmological disorders. To use OKNDrum simply place the iPhone or iPad in front of the eyes to elicit the response. The stripe color, width, speed, and direction can be adjusted easily. OKNDrum features: - 7 Scrolling Speeds - Red or Black Stripe Colors - Adjustable Scroll Direction - Adjustable Stripe Size - Easy-to-hide Menu - Easy-to-follow Instructions Feel free to contact us with any questions or feedback. *** OKNDrum was developed with the help of medical professionals and with the help of research papers. *** OKNDrum IS NOT a substitute for medical support. Consult your doctor for any advice.