A Brief History of Eye-Tracking

Ever notice how some websites seem to just flow, while others feel harder to navigate? There are many contributing factors in building usable web sites and applications, but one of the most interesting areas of research is eye-tracking.

Today, eye-tracking is used heavily by marketing groups to craft effective designs in advertising and by usability researchers to define the optimum user experience. This technology is anything but new though. In fact, eye-tracking goes all the way back to the 1800s.

Eye-tracking origins

In 1879, Louis Emile Javal noticed that people do not read smoothly across a page, but rather pause on some words while moving quickly through others.

Edmund Huey later built a device that was used to track eye movement in reading, and he published many of his findings in The Psychology and Pedagogy of Reading, still considered a profound work in the study of reading.

Huey’s device was quite intrusive however, and required readers to wear lenses that only had a small opening with a pointer attached to it. The device allowed Huey to observe where a reader was looking while reading, and he was able to study which words a reader would pause on.

Later developments in eye tracking technology arrived when Charles H. Judd developed the eye movement camera, a non-intrusive eye-tracking device that recorded motions of eyes on film allowing detailed study of eye motion. Along with Judd, Guy Thomas Buswell studied and analyzed eye movements in reading within different ages and levels of schooling. Buswell’s studies led to many leaps in the field of education and literacy, and also secured him a seat in the “Reading Hall of Fame.” He died recently at the remarkable age of 103, in 1994.

In 1931, Earl, James, and Carl Taylor created the Ophthalmograph and Metronoscope, devices used to record the movement of eyes while reading and tools that trained people to read more effectively. Essentially, it was understood that reading was not simply a smooth motion over words just as Louis Javal had suggested. Instead, a reader scans several words, pauses a moment to comprehend them, and then scans again (each scan is called a hop, and each pause is a fixation). The Ophthalmograph was used to measure a readers hops and fixations. Efficient readers would have a steady rhythm of hops and stares.

For readers that hadn’t developed an efficient reading style, the Metronoscope was used to establish this steady rhythm: a reader would be shown 1-3 words at a time through this special machine, and as they finish reading a set of words, a new set is shown. As a reader became used to this pattern, the machine would speed up, helping the user read more quickly by eliminating regressions and establishing a steady flow of words.

For many years, eye-tracking was used as a tool in education research and by medical researchers and physicians more than anywhere else because it was so expensive. It wasn’t until later in the century that it became more accessible to a new niche: marketers.

Eye-tracking used for marketers and designers

In the 1980’s, marketing groups really began using eye-tracking to measure the effectiveness of ads in magazines. Eye-tracking was able to determine what parts of a magazine page were seen, which elements of the page were actually read, and how much time was spent on each part. Previously, voice stress analysis and galvanic skin response tests were used to evaluate the effectiveness of ads (both forms of lie detection, that haven’t exactly been proven to work).

Eye-tracking research continued and led to better understanding in how our eyes and minds cooperate in digesting literature, problems, and images. However, it wasn’t really until the late 80’s and early 90’s that eye-tracking began to distinguish important differences in print and screen design.

In 1990, Gallup Applied Science’s eye-tracking system was used on NFL analyst Joe Theismann, and on average fans in the viewing of professional football games to determine what parts of the game the typical watcher missed. These devices filmed the user’s eye, and a computer would track where his eye followed the screen. After watching, a cursor marked on the film where the viewers were looking.

In the late 1990s, organizations including one of the world’s largest advertising and marketing agency networks EURO RSCG began using eye-tracking technology to measure and study reactions to information on the World Wide Web. For a large number of web designers up until this point, it was assumed that web design should be fashioned off of print and newspaper design.

In 2006, British behavioral consultancy research firm Bunnyfoot researched in-game advertising using eye-tracking and physiological data. The study examined how effective advertising was in video games in virtual worlds with digital billboards. Until recently, this has hardly been considered, but with the high demand of video games in today’s entertainment market, in-game advertising may become more prominent in the future (total sales in 2009 come close to $20 billion, compared to $10 billion in revenue from the box office).

From 2001 till present day, Tobii Technology has been developing eye-tracking technology that both allows disabled users to control devices using only their eyes, as well as helps designers understand how users view websites. One of their most recent product-launches includes the Tobii T60 XL Eye Tracker, the first widescreen eye-tracker. Like many of their other products, the Tobii T60 appears much like a usual computer monitor with built-in sensors that track eye movement and user reactions to different stimuli.

Eye-tracking and you

Today, eye-tracking is widely used in the scientific community, marketing, and in usability studies. This technology has seemingly become far more popular in the past decade than any other time in history, and is heavily used in developing effective advertising campaigns and usable websites. Access to this technology remains far beyond the average Joe however, with eye-tracking hardware often priced in the tens of thousands of dollars.

Jakob Nielsen, a pioneer in web usability, has authored a book Eye Tracking Web Usability which analyzes “…1.5 million instances where users look at Web sites to understand how the human eyes interact with design.” While this may not offer all the advantages of testing a self-developed web application with your own eye-tracking software, it absolutely will help reaffirm and reveal best practices based on many other online examples.

Also, while it does not replace eye-tracking by any means, click heatmaps do offer some useful feedback on websites, and are cheap to deploy and analyze.

There is work being done to reduce the cost of expensive eye-tracking equipment, and hopefully in the near future independent developers and designers will be able to cheaply conduct their own tests. Until then, following the research of others will continue to provide invaluable insight to a century-old area of study.