Richmond Products Inc
Richmond’s new Optokinetic (OKN) Drum accurately tests for nystagmus. When rotated at 8-10 rpm it allows a patient’s optokinetic reflex to follow objects in motion when the head remains stationary. The normal eye movements observed depend upon the orientation of the drum in front of the patient. The device may be used as an estimate of visual acuity. It is equivalent to a vision of counting fingers when held at a distance of 3 to 5 feet from the patient. The further the drum is from the patient, the better the visual acuity must be to respond normally to the moving drum.
The new Mini OKN Drum is 20 percent smaller than the previous model making it less cumbersome. It measures 8 inches (20 cm) in height, 6 inches (15 cm) diameter and weighs 25 ounces (708 grams). The lighter weight and smaller size make the drum much easier to use with the patient and takes up less storage space. The drum spins on ball bearings for effortless rotation. It is recommended to hold the drum 24 to 30 inches (61 to 76 cm) from the patient.