Where eye tracking is used as an interface
Eye tracking systems are not only used in connection with market research, but also in many other areas. Read this article to find out what technology is already capable of today.
What is eye tracking?
Eye tracking or eye movement measurement is a method that makes the eye movement of a person visible. The recordings consist of fixations and saccades. Fixations are those phases in which the eye rests on a point, while saccades are the movements of the eye between the individual fixations. Fixations are visualized as circles, where the diameter of the circle describes the duration of a fixation. Saccades are represented as connecting lines between fixations.
Eye-tracking can be used to measure and record emotions as well as to capture eye movements. This is done by measuring the pupil size, which depends on the emotions of the person and cannot be controlled or faked. However, this possibility is still used relatively little. In comparison, Face Tracking is already used quite frequently to capture emotions.
Which eye tracking technology is currently used?
Various technical methods are used to record the eye movements and their distribution. The following variants in particular are currently in use:
- Mobile Eye Tracking:Mobile systems essentially consist of an infrared light source, one or more cameras that record the reflection patterns on the cornea, and a field of view camera that captures the area the user is looking at. The cameras can already be accommodated in tracking glasses that are only slightly heavier than normal glasses.
- Eye Tracking via Webcam:The analysis of the eye movements is done by pattern recognition and algorithms.
- Eye Tracking Remote Systeme:Eye trackers are built directly into a monitor of a PC or laptop or mounted under or next to it. The eye movements are perceived contactless by infrared technology.
- AR/VR Eye Tracking:Glasses record the respective viewing directions in a virtually generated reality.
So there are both non-contact methods and those where glasses are worn to detect eye movement. The different methods can therefore be used to consider very different aspects.
Where is eye tracking used?
Eye tracking is used as an instrument in various areas. Among the most common applications are the following:
1. Eye tracking for user analysis in marketing
Numerous companies offer eye-tracking analyses as a service, in particular as an empirical basis for studies on the effectiveness of advertising campaigns, on the perception of products at the point-of-sale or on the evaluation of usability and customer experience of physical products or interactive applications, mobile applications or interactive products.
Eye tracking is therefore used to track the perception or gaze of test persons while they are performing a task such as ordering a product. Eye tracking tests, for example, are possible for:
- Websites (portals, online shops, web apps, intranets, job advertisements, product information, advertisements and spots, videos, etc.)
- Advertising materials (catalogues, magazines, print advertisements, posters, PDFs, etc.)
- TV commercials, videos
- Training and accompanying materials (e.g. instructions for use)
- Kiosk systems (terminals, vending machines, etc.)
- Point-of-Sale (shopping centers, fairs, supermarkets, etc.)
- Mobile (Apps, Tablets, Smartphones, E-Reader, etc.)
- Home Entertainment (TV set, SmartTV, game consoles, HiFi, etc.)
- Products (product design, packaging design, out-of-the-box, product variants, product information, etc.)
- Software (application software, games, cloud software, etc.)
- Guidance systems/signposting (shops, museums, exhibitions, events, etc.)
For the graphical evaluation of the eye-tracking user analyses, the following visualization methods are used in particular:
- Heat Maps:The Heat Map visualizes how long or how often certain areas are viewed. It is primarily used for the aggregated representation of several persons. The longest or most frequently viewed elements are highlighted in red, while only briefly or rarely viewed elements are highlighted in green.
- Opacity Maps:This is the negative image of a heat map. All areas, which are not considered, are darkened. The bright areas show where the user draws his attention.
- Gazeplots: Gazeplots visualize the course of the gaze. The numbering of the circles shows the order of the observations, the size of the circles gives information about the duration of the observation. A gauze plot can be viewed both statically and as an animation.
For deeper analyses, other analysis techniques are used, such as parallel scanpaths, visualizations for special areas (Areas-of-Interest) or space-time cubes in 3D space. The following clip shows what an evaluation can look like in practice.
2. Healthcare sector
Numerous manufacturers of communication aids now also offer control options via eye tracking. For example, people with severe motor impairments, such as advanced multiple sclerosis or severe physical disabilities, can only control a communication aid or a computer via eye movements.
Further applications can be found in ultrasound surgery. For example, eye trackers are used for laser treatment of ametropia to monitor eye movements to ensure that the laser treats the cornea at the planned site. Other systems can be found in the fields of neurology, balance research, oculomotor functions and eye malpositions.
Eye-trackers are also gaining more and more importance in psychiatry. They are used for image and movement perception as well as for the analysis of learning progress. In the case of anxiety or eating disorders, for example, there are conspicuous information processing processes that can be recorded by measuring gaze data. In the future, more reliable and earlier diagnoses should also be possible, e.g. for autism or ADHD. To facilitate research in psychology and neuroscience, Tobii Pro has already developed an eye-tracking solution that can be integrated behind the lenses in the HTC Vive VR glasses.
A large field of application for eye-tracking in the medical field can be found in training. Experts or specialists can see in trainings, simulations and in telemedicine exactly what students, nurses, task forces or doctors see on site. At the Herzklinik Berlin, for example, the Tobii Pro Glasses 2 tracking glasses are used in student training.
3. Applications in industry
Industrial eye tracking can reduce downtime, save personnel costs and provide a higher level of service. Mobile eye-tracking systems are already used in human-machine interaction to increase user-friendliness. It is also possible to check the efficiency of the operation of terminals and control centers. Other possible applications include lean operations, remote support, service maintenance, audit controls, workplace ergonomics and organization, safety training for employees, factory acceptance tests and service level agreements.
Especially due to digitalization, experts expect the eye-tracking technology at the human-machine interface to become more widespread in the coming years.
They are already working on a robot control via eye-tracking. The German Research Center for Artificial Intelligence (DFKI) is currently developing Hitachi, an AI technology that detects critical actions and device errors in the production line at an early stage on the basis of eye direction and motion sensors. Deep learning algorithms process data from eye tracking glasses and wristband sensors. The combination of visual (eye tracking glasses) and physical (sensor wristband) data is intended to optimize work processes that require intelligent assistance and error detection.
4. Eye Tracking and Virtual Reality
Especially in the development of games, the use of eye tracking is used to improve the experience in virtual reality and augmented reality. Eye Tracking enables the so-called Foveated Rendering (FOVR). This only fully renders the area on which the focus is currently on. Elements, which are not considered, can be faded out with it almost completely. If, for example, you do not look straight at the compass, it becomes almost completely transparent and disappears from the peripheral field of view as far as possible. The viewing direction can also be used to control the in-game camera.
Apple is also working on a combination of eye tracking and VR. While the face tracking technology for emotion tracking is already capable of distinguishing around 50 different facial expressions, experts expect the company to launch its first Apple AR glasses in the course of 2020. Since Apple has already been buying up AR companies for several years, there are many indications that the company is developing a new device category with the AR kit that could possibly even replace the iPhone. With AR-Kit 2, which is part of iOS 12, Apple has already integrated some promising new functions with iOS 11 after the introduction of the Augmented Reality platform, which could also be used in AR glasses. Among other things, it is already possible to make entries via eye-tracking.
VR Eye trackers can also be used profitably to implement expensive studies at considerably lower costs, since virtual environments can be quickly adapted to the respective problem. Behavioral research on e.g. arachnophobic patients could be carried out more efficiently and with less risk. Research on work processes in medicine or production is also mentioned as one of the ways in which VR and eye-tracking can be used to increase efficiency in a wide variety of areas. Also the training of e.g. pilots is an application possibility.
Conclusio: Where eye tracking is used as an interface
The classic fields of application of eye tracking technology are found in market research and psychology. However, new methods are making new areas such as usability optimization, medical examinations or industrial applications increasingly important. However, it must be carefully considered whether this method should be used, since costs and effort are still relatively high. If one wants to use the method, experts should be consulted.
Born in Vienna. Since 2018 "Certified Service Design Thinker" he has been pursuing his passion as Innovation Manager at LEAD Innovation.