Oculometer

Oculometer is a device that tracks eye movement. The oculometer computes eye movement by tracking corneal reflection relative to the center of the pupil. An oculometer, which can provide continuous measurements in real time, can be a research tool to understand gaze as well as cognitive function. Further, it can be applied for hands-free control. It has applications in flight training, cognitive assessment, disease diagnosis, and treatment. The oculometer relies on the principle that when a collimated light beam is incident on the eye, the direction in which the eye moves is proportional to the position of the reflection of that light beam from the cornea with respect to the center of the pupil. Eye movements can be accurately measured over a linear range of more than 20 ^\circ with a resolution of 0.1 ^\circ .

Oculometer is a device that tracks eye movement. The oculometer computes eye movement by tracking corneal reflection relative to the center of the pupil. An oculometer, which can provide continuous measurements in real time, can be a research tool to understand gaze as well as cognitive function. Further, it can be applied for hands-free control. It has applications in flight training, cognitive assessment, disease diagnosis, and treatment. The oculometer relies on the principle that when a collimated light beam is incident on the eye, the direction in which the eye moves is proportional to the position of the reflection of that light beam from the cornea with respect to the center of the pupil. Eye movements can be accurately measured over a linear range of more than 20 ^\circ with a resolution of 0.1 ^\circ . D=\kappa*sin \theta D is displacement, \kappa is the distance from the center of the cornea, \theta is the angle of inclination of the eye's optical axis to the oculometer. Near infrared light (NIR) (approximately 750nm to 2,500nm wavelengths) is used for a few reasons. First, NIR light is less detectable to the human eye than other wavelengths of visible light, so the NIR light beam is less intrusive or noticeable to the user. Second, with this configuration the pupil is backlit, resulting in a bright disc, effectively differentiating the pupil from the rest of the eye and face. Typically, the oculometer consists of an eyepiece through which the user sees. An alternate design exists where the oculometer is head-mounted. This arrangement does not include the traditional eye-piece and user sees through a transparent, curved visor placed in front of his eyes. ===Diagnosis of Parkinson's disease=== Abnormal eye movements is an established biomarker for numerous motor diseases including Parkinson's disease. Each motor disease is expected to produce different signature pattern of eye movement abnormalities. Using those eye movement patterns both as a diagnostic tool and for monitoring disease progression has therefore been of scientific interest. Oculometers are therefore used in this area for tracking eye movement. The use of oculometers for diagnosis of motor diseases is promising, though it has not yet been validated in the clinic. For Parkinson's disease specifically, the signature pattern of eye movement abnormalities occur as horizontal saccades (rapid, conjugate, eye movement that shift the center of the vision field). Patients with Parkinson's disease displayed high inabilities in performing antisaccadic tasks (eye movement in the opposite direction from the onset trigger). Measurement of antisaccades therefore enables scientists to detect early stages of Parkinson's disease. These studies are still in the research phase.

Text derived from https://en.wikipedia.org/w/index.php?oldid=1319555818 under CC BY-SA 4.0; modifications have been made.