1. EYE MOVEMENT BASED HUMAN COMPUTER INTERACTION
TECHNIQUES: TOWARDS NON-COMMAND INTERFACE
BY
RAJ KIRAN
09B91A0586
GNITC

2. The Eye
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Eyes are the windows of the soul.
 Eye are the parts which perceive light in our human
body.
 Interaction with other body parts.
 A Combination of eyes and brain help us in
processesing complex visual information.

3. How We See ?
Eye Movement Non-command
Introduction Conclusion
Tracking Interface

4. Physiology of Eye
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Cornea is a transparent structure that
covers the iris and pupil; a part of the
focusing system of an eye.
 Pupil is the adjustable opening at the
center of the iris that allows varying
amounts of light to enter the eye.
 Lens helps to focus light on the retina.
 Retina includes rods (94%), which are
sensitive to light and cones (6%) that
capture colors. Cones are
concentrated in the centre of the
retina - the fovea

5. Facts about Human gaze
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 One’s eye is rarely stationary.
 Eye movement reflects a viewer’s visual information
process.
 The eyes can move faster than the hand.
 Eye movement consists of:
 Saccades
 Fixations

6. Eye tracking Technology
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 What is Eye tracking?
 Eye tracking is the measurement
of eye activity.
 Why use eye tracking ?
 Gives an accurate measure of where one’s looking.
 Enhances or back-ups observations.
 Can lead to many potentially useful applications.

7. Techniques for measuring eye movements
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Measuring Visual line of gaze (Where he or she is looking in
space).
 Different techniques used for measuring eye movements.
 Skin Electrodes
 Contact lens
 Head Mounted
 Remote System

8. Techniques for eye tracking: Skin Electrodes
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Electrodes placed on the skin around the eye socket.
 Measuring the electrical differences between retina and
cornea.
 GOOD POINTS:
 Both eyes can be recorded together
 Least expensive
 Simple to use
 DOWNFALLS:
 It is limited to horizontal and vertical movements
 Poor accuracy for absolute positioning

9. Techniques for eye tracking: Contact lens
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 A non-slipping contact lens fits over corneal bulge.
 Tracking is recorded by affixing a magnetic coil or mirror to the
lens.
 GOOD POINTS:
 Provides accurate data about the
nature of human eye movements.
 DOWNFALLS:
 Extremely awkward, uncomfortable for the user.
 Interferes with blinking.
 Covers only a limited range of eye movements.

10. Techniques for eye tracking: Head Mounted
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Small camera and light source mounted to users head via a
headband or helmet
 Reports the angle of the user’s eye with respect to his or her
head.
 Two data sources can determine the line of gaze in physical
space.
 GOOD POINTS:
 Doesn’t restrict the user’s head movements
 DOWNFALLS:
 More awkward to use than the desk-based
system as the user has to have instrument
mounted to head.

11. Techniques for eye tracking: Remote System
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Most practical method of eye tracking.
 Uses Illuminator/eye camera.
 Tracking visible features of the eye.
 Head movements can be distinguished
from eye movements by tracking 2 points.
 GOOD POINTS:
 Allows for a fair range of head movements
 Accurate, fast and affordable
 DOWNFALLS:
 Head still needs to stay within camera range.
 Delicate to calibrate and operate

12. Current Challenges
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Midas Touch problem
 Jitter of eye
 Multiple “Fixations in a single Gaze”
 Instability in eye Tracking Equipment

13. Non-command Interface
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Non-command interaction
 Interaction Techniques
 Object Selection
 Moving an object
 Eye controlled scrolling text
 Menu commands
 Listener window

14. Towards and beyond Non-command interfaces
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Command Style
 Interactivity
 New Interface Styles
 Beyond Windows System

15. Interactive Applications
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Accessibility
 System Enhancement
 Non-Command Based Systems
 Virtual Displays

16. Interactive Applications: Accessibility
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Eye tracking can allow people to use their eyes to
communicate
 Because the ability of some handicapped individuals to
operate other devices is limited or nonexistent.
 The eye movement interface need to perform only
minimally well to provide a significant benefit.

17. Interactive Applications: Non-command based systems
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Non-command based system
 The system passively monitors the user and responds
as appropriate, rather than waiting for the user to issue
specific commands.
 EX : Gamming Applications

18. Interactive Applications: System Enhancement
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Mainly used for the users whose hands are occupied
 Potential Problems:
 Some will find the eye movement based interface better
(faster, more convenient and more natural) while others
may feel uncomfortable.
 Too unnatural to use in critical situations?
 Eye tracking may be best used to act as
a supplemental input or display method.

19. Interactive Applications: Virtual Displays
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Making VR more realistic
 If accurate, the user cannot detect the difference between
this arrangement and the large, high-resolution display it
emulates.

20. A Case Study on Tobii T120 Eye Tracker
Tobii T120 Eye Tracker
Tobii T120 Eye Trackers enable you to conduct on-screen
eye tracking studies for a wide variety of research purposes. It
delivers reliable results in a natural testing environment

21. A Case Study on Tobii T120 Eye Tracker
Figure : Overview Of Eye Tracking System

22. A Case Study on Tobii T120 Eye Tracker
Corneal reflection
Figure : Working of Eye Tracking System
 Initially position and orientation of eye are determined.
 The Gaze Point is found at the intersection of optical axis and
the viewing plane

23. A Case Study on Eye Tracking in Cognitive Science
Visual Search
 Physical and cognitive processing limitations can prevent us
from instantly recognizing the presence of a target item in a
single glance.

24. A Case Study on Eye Tracking in Cognitive Science
Method
Subjects had to look for a specific object within a visual scene.
 Target could be specified by a word or a picture. Pictures
specify the target template more elaborately than words.
 To manipulate the time that the subject had to build up a
target template and keep it salient in memory.
 To manipulate target familiarity, the target specification was
either shown 4 times to the subject prior to experiment.

25. A Case Study on Eye Tracking in Cognitive Science

26. A Case Study on Eye Tracking in Cognitive Science
Results
Picture rather than word resulted in:
 Faster total search times
 Shorter scanning and verification times
 Fewer regions visited
 Shorter scanning fixation durations (rejection of
distractors)

27. Conclusion
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 An Eye tracker as an input device is far from “perfect”
 The approach in designing interaction techniques should be
more efficient
 We can view eye movement-based interaction as an instance of
an emerging new style of user-computer interaction
 It is helpful for usability studies to understand users interact
with their environments
 Potentially could provide new and more effective methods of
computer-human interaction

28. Conclusion
Eye Movement Non-command
Introduction Conclusion
Tracking Interface
 Potentially could provide new and more effective methods of
computer-human interaction
 It is amazing that eye movement-based interaction can be done
at all
 The Technology is still improving, and is “not quite there” yet –
but has an exciting future!