Purpose: Accurate measurement of the direction of gaze is essential for various ophthalmological examinations such as in perimetry. We have developed a new eye tracking system which extracts the gaze direction from video images of the eye. Methods: Video sequences of eye movements were recorded using the built-in video camera of an Oculus TAP 2000 perimeter. Gaze eccentricities of 0 deg, 4 deg, 12.5 deg, 22.5 deg and 30 deg were aquired and digitalized. An eye tracking software was developed to analyse and calculate the gaze eccentricities from video frames. The accuracy of the calculated eccentricities was determined by comparison to the known eccentricity values. Results: Gaze eccentricities could be measured with an average accuracy of less than 1 degree. The reproducibility of gaze determination based on 10 consecutive measurements reaches 0.23 degrees. Conclusions: A precise method for video based eye tracking has been established. Any video input can be used, including sequences recorded with the video cameras built into perimeters. This method can facilitate gaze analysis in various visual tests and thus allow for automated gaze control systems in ocular examination.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience