In the simplest terms possible, eye tracking is „following the trail of where a person is looking”. The definition is not ours, but of the researchers Nielsen and Pernice. As simple as it sounds, collecting, analyzing and understanding the data acquired through eye tracking is a process that requires great effort: not only experience, but time.
However – and maybe it will surprise you – eye tracking is not novel. The technology has been around for more than 100 years now, but it was reborn and rediscovered in the last years as a real Phoenix. Let’s see some highlights about the evolution of the eye tracking technology until today.
It’s difficult to pin the exact inventor of eye tracking. We can say that the first one who studied it was the French ophthalmologist Javal, who defined fixations (pauses) and saccades (quick movements) of the eyes as early as 1879. His studies used naked-eye observations.
However, the inventor of the first eye tracking device is Huey. In 1908, he built a device that consisted of lenses with small openings and a pointer attached to them. The device could tell where was focused the gaze of a reader. It was invasive and involved direct mechanical contact with the cornea, thus it was very different from the eye tracking device as we know it today.
The first non-invasive eye tracking technique was invented in 1901 by Dodge and Cline, who used light reflected from the cornea. Even though the method was quite precise and non-invasive, it required the head to stay steady during the investigation and it recorded only horizontal eye position.
Not long after, in 1905, temporal aspects of eye movements could be recorded in two dimensions due to the technique developed by Jud, McAllister and Steel. They used motion picture photography instead of light reflected from the cornea.
The first application of eye tracking in usability engineering was in 1947, when Paul Fitts and his colleagues studied the eye movements of pilots while the pilots were using cockpit controls and other instruments to land an airplane. They used cockpit-mounted mirrors and movie cameras to capture and analyze eye movements. In other words, for the first time, researchers studied how users interact with a product, with the aim of improving product design.
Participants in eye tracking studies received greater freedom of movement along with the invention of a head-mounted eye tracker in 1948. However, the head-mounted devices were greatly improved by other specialists after their launch, in order to make them even less obtrusive and to reduce even more the restrictions on head movements.
Not only advances in the technology are worth mentioning. The eye tracking research flourished after the ‘70s, along with advances in psychology and cognitive psychology. To make use of eye tracking, it was needed to understand how the human eye operates and what it can reveal about perceptual and cognitive processes.
Used for medical and education research, eye tracking started to look appealing to marketers after the ’80s. Its first application was to assess the effectiveness of a magazine ad – what exactly was seen by the readers.
In the late ’90s, the marketing agency EURO RSCG used eye tracking for analyzing and measuring how users interact with the content on the Internet. The aim was to improve the web pages effectiveness. From then, eye tracking started to be used for user research in a great number of fields, from digital products to sports and eSports. The great advantage of this technology is that it can be adopted by any domain, as it reveals real, subconscious and objective data about users.
There are many stages and people worth mentioning when talking about the development of eye tracking. Many pages can be written on this subject, but we wanted to give you only the highlights of its history. Even though eye tracking has been around for more than 100 years, it is still considered cutting-edge technology that, unfortunately, not many professionals have the chance to use.