This device accurately tests for the presence of Nystagmus when rotated at 8 to 10 rpm in both children and adults. It is of lightweight construction and rotates smoothly and effortlessly. For use at 60 to 75 cm from the patient.

The OKD can be stored safely as it can stand on its top with the handle protruding upwards - this prevents the unit from rolling off surfaces when not in use. Dimensions: 25 cm high with a 16 cm diameter.