Video-oculography (VOG) is a non-invasive, video-based method of measuring horizontal, vertical and torsional position components of the movements of both

eyes Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conve ...

(

eye tracking Eye tracking is the process of measuring either the point of gaze (where one is looking) or the motion of an eye relative to the head. An eye tracker is a device for measuring eye positions and eye movement. Eye trackers are used in research ...

) using a head-mounted mask that is equipped with small cameras. VOG is usually employed for medical purposes. __TOC__

Technology

The measurement of the horizontal and vertical components is well established technology which uses pupil tracking and/or corneal reflection tracking and has been widely applied, for example for tracking

eye movements in reading Eye movement in reading involves the visual processing of written text. This was described by the French ophthalmology, ophthalmologist Louis Émile Javal in the late 19th century. He reported that eyes do not move continuously along a line of text ...

. In contrast, the measurement of the torsional component (cyclorotation) is usually considered a computationally more difficult task. Approaches to solving this problem include, among others,

polar Polar may refer to: Geography Polar may refer to: * Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates * Polar climate, the c ...

cross correlation In signal processing, cross-correlation is a measure of similarity of two series as a function of the displacement of one relative to the other. This is also known as a ''sliding dot product'' or ''sliding inner-product''. It is commonly used fo ...

methods and

iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants *Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional enti ...

pattern matching In computer science, pattern matching is the act of checking a given sequence of tokens for the presence of the constituents of some pattern. In contrast to pattern recognition, the match usually has to be exact: "either it will or will not be ...

tracking Tracking may refer to: Science and technology Computing * Tracking, in computer graphics, in match moving (insertion of graphics into footage) * Tracking, composing music with music tracker software * Eye tracking, measuring the position of t ...

. In animal studies, VOG has been used in combination with

fluorescent marker In molecular biology and biotechnology, a fluorescent tag, also known as a fluorescent label or fluorescent probe, is a molecule that is attached chemically to aid in the detection of a biomolecule such as a protein, antibody, or amino acid. Gener ...

arrays affixed to the eye, and it has been proposed that such an array could be embedded into a

scleral lens A scleral lens, also known as a scleral contact lens, is a large contact lens that rests on the sclera and creates a tears, tear-filled vault over the cornea. Scleral lenses are designed to treat a variety of eye conditions, many of which do not ...

for humans.

Use

VOG techniques have been put to use in a wide field of scientific research related to visual development and cognitive science as well as to pathologies of the eyes and of the visual system. For example, miniaturized ocular-videography systems are used to analyze eye movements in freely moving rodents. VOG can be used in

eye examination An eye examination is a series of tests performed to assess vision and ability to focus on and discern objects. It also includes other tests and examinations pertaining to the eyes. Eye examinations are primarily performed by an optometrist, op ...

s for quantitative assessments of ocular motility,

binocular vision In biology, binocular vision is a type of vision in which an animal has two eyes capable of facing the same direction to perceive a single three-dimensional image of its surroundings. Binocular vision does not typically refer to vision where an ...

vergence A vergence is the simultaneous movement of both eyes in opposite directions to obtain or maintain single binocular vision. When a creature with binocular vision looks at an object, the eyes must rotate around a vertical axis so that the proje ...

cyclovergence Cyclovergence is the simultaneous occurring cyclorotation (torsional eye movement (sensory), movement) of both human eye, eyes which is performed in opposite directions to obtain or maintain single binocular vision. Normal cyclovergence and cyclo ...

stereoscopy Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word ''stereoscopy'' derives . Any stereoscopic image is ...

and disorders related to eye positioning such as

nystagmus Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement. Infants can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in reduced or limited vision. Due to the invol ...

and

strabismus Strabismus is a vision disorder in which the eyes do not properly align with each other when looking at an object. The eye that is focused on an object can alternate. The condition may be present occasionally or constantly. If present during a ...

. It has also been proposed for assessing linear and torsional eye movements in vestibular patients and for early stroke recognition.Hopkins Stroke Detector Uses Video-Oculography for Faster Diagnosis
medgadget.com, 7 March 2013 (downloaded 11 July 2013)

References

{{DEFAULTSORT:Video oculography Cognitive science Multimodal interaction Eye procedures Stereoscopy