Maybe you have heard or read about it: eye tracking. Eye tracking is a technique that measures where a user is looking at. The point that is being tracked is called the point of gaze.
Eye tracking works by sending an infrared light towards the centre of the eye. This causes a visible reflection in the cornea (the outermost optical element of the eye). These reflections are tracked by an infrared camera.
Some people refer to eye tracking as head tracking. However, both techniques are not the same. Head tracking only measures where the head is pointed towards. Therefore, the tracking is not as accurate because it measures everything that is in the line of sight.
Interview with Robbin and Kubilay
To learn more about the uses of eye tracking, we have interviewed Robbin and Kubilay. Robbin and Kubilay are both VR and AR developers and have a lot of experience with eye tracking.
Where is eye tracking used in the year 2019?
“At the moment it is mostly used for analysing.” Robbin explains. “Take a supermarket for example. When a new shop opens in America the shop lets a certain amount of people walk through the store with eye tracking glasses. The glasses measure where shoppers are looking at and what paths they take. This information is used to improve the shopping experience”.
Kubilay: “During VR training simulations, eye tracking is used to review what the trainee is doing. After the training they can analyse what choices have been made and where they were looking at. Also, marketing can use it for analysing what their customer actually cares about in a commercial”.
“During software development, eye tracking can be used to increase the performance of VR applications. The eye tracking measures where we are looking at, so only that part of the application is rendered in full quality. “The rest is left blurry.”, as Robbin told us. The performance increase happens, because it takes a lot less compute power to render a blurry image then a full focus image. The extra render power can be used elsewhere.
“Occlusion Culling is a technique that makes sure only the objects that are visible are being rendered. So, for instance if an object is behind a wall it will not be rendered. LOD, short for Level of Detail, decreases the detail in object that are far in the distance. And if you come closer it increases the detail. Both these techniques, in combination with eye tracking, dramatically increase performance”.
According to Kubilay, eye tracking also helps with controlling menus in software. “If both hands are occupied by controllers, eye tracking makes is easy to navigate a button.” Microsoft announced that the HoloLens 2 supports eye tracking. It is used to control the menu’s and many other things.
Robbin: “Eye tracking, in combination with VR makes controlling games much easier. During tests they saw that it is much easier to precisely throw a ball through a basket with eye tracking, than without it. This happened because eye tracking lets you really control your aim, like you do in the real world”.


Possibilities in the future?
“Everything will become more affordable”, according to Kubilay. “Known brands such as Oculus and HTC will support eye tracking in their new devices. Other companies are working on it as well. In Asia you can already buy multiple VR devices that support eye tracking”.
“Now we still use infrared and cameras to track our eyes. In the future we will have screens that use light reflections to measure where the eyes are looking at. The technique is still in early stages. They use 45 screens simultaneous to display an object. This gives the effect of a 3D object. “Glasses are becoming smaller. Imagine normal reading glasses but with advanced technology like eye tracking and AR”.
Robbin: “We believe that XR is completely going to replace every smartphone. XR is a collective term for VR and AR. Imagine having all your important data all around you instead of on the phone. AR is going to be used on billboards for more realism. The eye tracking measures where we are looking at”.
What will become the biggest use case?
“Analysing with eye tracking will have a big impact. It will be much better to predict how people will react to something. In games, the performance increase will also help to make it more affordable because less powerful hardware is needed to render the same image”.
Robbin: “We collect more data in one day than we did in a year 30 years ago. With the information of eye tracking big data will become more reliable and smarter because eye tracking information is super accurate. Data is now more imported than ever. Like Dutch people always say: “meten is weten”(measuring is knowledge).
Kubilay: “For UI/UX designers, eye tracking is going to make a big difference. Instead of normal testing you can use eye tracking to test if the design is having the desired effect. Because of the accurate tracking, we know exactly where people are looking at when they use the software. Just like the supermarket, they can change their design based on the information”.
Biggest market that is going to change because of these new developments?
Kubilay: “Like we said earlier we believe that the smartphone as we know it, is going to disappear. VR and AR are going to replace it. This will not take that long. We think in about 5 to 10 years this will have happened. Also driving lessons could completely change. The instructor could accurately analyse if a student is really using their mirrors. With the use of VR, a part of driving lessons can be replaced by virtual ones. After a virtual lesson the student and instructor can have a full debrief of the lesson”.
Robbin: “Also in processing traumas or fears VR is going to be a game changer. We can help autistic children more effective than with traditional methods. Their environment can get an insight in their world, so they understand it better. The possibilities are endless. Take ex-prisoners for example. With eye tracking we can monitor their behaviour much more accurate than a prison ankle bracelet”.