To study behaviour during reading and writing, R&D Vision has developed a system for analysing gaze direction.
A tablet containing texts to read was designed using Solidworks, then produced by stereolithography. The tablet includes high speed imaging (100Hz), LED NIR lighting and specific control electronics. The algorithms used to track the pupils and the reflection of the cornea were developed by R&D Vision and adapted to the constraints of using the system (wearing glasses, for example). The system allows tracking of both eyes simultaneously and has a precision of a few millimetres in the reading zone.
At the same time as this measurement, the direction of the head is trackedand this is used to determine the position of the tablet in absolute terms, as well as the attitude of the subject.