We often take our eyes for granted. Do we know what our eyes are actually looking at?
It is actually rather difficult to be conscious of what our eyes are looking at because we’re busy processing the information they are focussing on. Not only that but the scanning speed is incredible.
Have you ever wondered how our eyes plan a journey, for example, on a subway map?
Using the latest technology and collaborative team effort it is now possible for us to see what our eyes are actually ‘doing’ when they look over a route map.
It has been a great pleasure for me to work with a brilliant team of scientists at the German University of Stuttgart, Visualisation Research Centre (VISUS) led by Professor Daniel Weiskopf and his colleagues Dr. Michael Burch and Rudolf Netzel, Dipl.-Inf., and Bettina Ohlhausen in a collaborative effort to study the effectiveness of both colour and black & white schematic transport maps in journey planning.
In a world-first study, using 24 schematic maps I had previously designed for my associate company Communicarta, a variety of cities representing a variety of complexities, the team at VISUS measured task accuracy and task response time with the assistance of 40 volunteer participants. The accuracy was 100 percent and the response time was good – meaning all of them could answer the tasks reliably in a short time.
It is possible to study the eye movements of each of the participants for each of the journeys they were asked to plan and to make conclusions from the data analysis.
The full Paper, well worth the read, is available to download. User-Performance-and-Reading-Strategies-for-Metro-Maps
After the year–long study, analysis and paper authoring I was invited to take part in a quick demonstration of the study set-up during a visit to Stuttgart in November 2015. And a fascinating experience it was too. Sitting in front of a computer screen with a map I am very familiar with – New York subway – having originally designed it in 1993 and continuously updating it ever since, didn’t take away the excitement from experiencing even a small part of the overall experiment.
In front of the screen and not moving my head whilst the machine was calibrated for my height and eyes, I couldn’t help but marvel at what wonders science can provide us with. Near-infrared light is emitted from the bottom of the screen up towards the eyes where it is reflected onto the screen so as to track and measure the eye movements. Fascinating stuff!
Apparently the machine used can measure 60 movements per second. I find that statistic quite astounding.
Here is an example of a typical setup for eye tracking in a laboratory. To read more specifically about eye tracking systems follow this link to the site of the manufacturers equipment used in this study, Tobii Pro.
In the video below you will see a green hand pointing to a station on Line 1, which is the starting point, and the destination station shown with three red target rings. Upon pressing play you will see small red dots appearing in a variety of places around the map – that’s a record of what my eyes are ‘doing’. You will also sometimes see thin red lines linking the red dots. This is where there is a more continuous ‘focus’ between those points.
Bear in mind that the video is a consolidation of all the eye movements put together to be able to ‘show’ what happens. Much data has been gathered and would need to be fully interpreted to be fully useful in the study. This was done for me to experience what eye tracking actually ‘looks’ like.
You will also see, from time to time, a red dot becoming enlarged. This is where my eyes are fixing on one location for an extended period of time.
So that’s it – a glimpse into the wonderful and exciting world of eye tracking – in this example, a subway map. And here it is…