A handheld testing device includes a focus light source, which can serve as a focal point for a subject being tested for nystagmus, and multiple timers, which can be used to control tactile and other feedback indications. The timers can include an Equal Tracking (ET) timer and Smooth Pursuit (SP) timer, each of which controls a series of tactile feedback indications that can assist a user in properly performing ET and SP portions of a Horizontal Gaze Nystagmus test. Other test timers configured to generate feedback indications for use in various medical examinations and drug evaluations are also included. The handheld device can include multiple light sources in addition to the focus light source, for example an ultra-violet (UV) source or a white light source. Various fixed interval timers can also be included in the handheld testing device.
