A dynamic pupillometer, using an infrared scanning system, allows for small eye movements and out-of-focus movements, without affecting the recording of a pupillary reaction. The area around the pupil as scanned every 1/45 sec. The number of scanning lines and the dimensions of the scanning spot are such, that the error in the determination of the pupil diameter is about 0.1 mm. This diameter is determined from the number of scanning lines that "hit" the pupil. The value of this diameter is available at the output of the pupillometer as a digital number or as an analog voltage.
Abstract