Optokinetic nystagmus test
Codev produce an optical toolkit for eye examinations called OptOK that includes a test for optokinetic nystagmus (jerking eye movements). I have created a free version of the optokinetic test available here as an Adobe Flash applet, or to download as a standalone application (Adobe Air must be installed before downloading). For the full toolkit download, including a more advanced and friendly version of the optokinetic nystagmus test, download OptOK for your iOS device.
Simply move the slider or back to start the stripes moving at the desired speed (in pixels per second) – or enter the value manually in the text box – then look for nystagmus (jerking eye movements). Stop the movement by pressing pause. Optokinetic nystagmus is a normal reflex, so patients with functional blindness will have preserved OKN. Nystagmus that persists once the moving stimulus is stopped may be abnormal.