Accurate three-dimensional eyetracker

Autor: Hewitt D. Crane, Carroll M. Steele
Rok vydání: 2010
Předmět:
Zdroj: Applied optics. 17(5)
ISSN: 1559-128X
Popis: A three dimensional eye tracker, for measuring as a function of time the point in three dimensional space on which the eye is fixed, includes a portion which functions as a two dimensional double Purkinje eye tracker for measuring movement of the eye in rotation and translation, an automatic optometer portion for measuring the refractive power of the eye, and a common optical path simultaneously to provide corrections for both portions of the instrument. The two dimensional eye tracker portion incorporates a means for directing a beam into the eye, thereby forming first and fourth Purkinje images, and measuring means responsive to the first and fourth Purkinje images to generate output signals indicative of eye rotation and translation. The automatic optometer portion alternately directs a light beam through different areas of the eye lens and includes a mechanism for altering the directed light beam until the image on the retina does not move. The common optical path for the light beams includes elements that stabilize the eye image in a way to make alignment of the subject in the instrument relatively easy and also to avoid errors both in measurement of refractive power and for direction of gaze due to translation and axial movement of the eye. Polarizers and mechanical stops are incorporated in the optometer portion to provide optical isolation between the eye tracker and the optometer portions, and electrical filtration is provided in both portions of the instrument further to avoid interference.
Databáze: OpenAIRE