The history of eye tracking research dates back to the 80s. of the nineteenth century, when in Paris Louis Émile Javal began the measuring of the eye movements using external device. His method required contacting the device to the surface of the eye, so it was the invasive method – the eye contacted the lens combined with aluminum indicator, which reported on the eye movements.
The first non-invasive eye tracker was created in the USA in 1901. This device was directing the light beam reflected from the eye onto a moving light-sensitive photographic plate, which made it possible to do the recordings of eye movements. However, at that time it was possible to record only horizontal movements. Only a few years later was created the machine that made it possible to study both vertical and horizontal movements.
Over the years, the eye-tracking equipment and research were developing. The next stage in the development of measurement technology was a convenience of a stable mounting of the measuring instrument to the proband. In the 70s and 80s the number of eye tracking studies had increased. At that time the main topic of the studies was the process of reading, but eye tracking was also involved in aviation and space medicine.
The high level of computer software and video cameras caused an essential change in eye tracking research. As the results, the research results could be used in market research, and also in testing the quality and ergonomics of use of websites. Currently used photoelectric eye tracker can record eye movements through the changes in the reflected light on the cornea of the eye of particular speaker-listener during translation/ interpreting. The texts are presented on LCD monitor, and a mini video camera installed on the monitor records the movements of both eyes. The digital image obtained during the experiment has a very high accuracy, i.e. measuring at the frequency of 500 Hz (in the devices installed on the monitor (as in SMI's RED 500) and of1250 Hz in specially constructed devices (compare: SMI Hi-Speed Eye Tracking).
[Anna Bonek, Marta Najman]