3. Eye Tracking
History
Significance of Eye Tracking
The Process Of Eye tracking
Techniques used for measuring eye movements
Some Devices
Advantages
Application
Conclusion
4.
5. What is Eye Tracking?
In the simplest terms, eye tracking is the measurement of eye activity. Where
do we look? What do we ignore? When do we blink? How does the pupil
react to different stimuli?
Eye tracking is the field of monitoring what people do with their eyes –
observing what people choose to look at, how their eyes move, how their
visual activities behave. Eye trackers are the instruments that measure our
eye behavior.
The concept is basic, but the process and interpretation can be quite
complex
6.
7. Significance of Eye Tracking
Our eyes and vision systems are our brain’s primary tools for gathering
current information about our environment.
With eye trackers researchers can observe what our brains choose to
look at.
While eye tracking instruments cannot explain why our brain chooses
to look at specific things, they do measure and record the sequence of
visual pointing decisions the brain ultimately makes
8. THE PROCESS OF EYE TRACKING
Eye tracking data is collected using either a remote or head-mounted
‘eye tracker’ connected to a computer
While there are many different types of non-intrusive eye trackers
They generally include two common components:
a light source
a camera.
9. The light source (usually infrared) is directed toward the eye.
The camera tracks the reflection of the light source along with visible
ocular features such as the pupil
This data is used to extrapolate the rotation of the eye and ultimately
the direction of gaze
Additional information such as blink frequency and changes in pupil
diameter are also detected by the eye tracker
10. • Many modern eye trackers are based on video cameras that observe
our eyes and produce high-resolution images of our irises, pupils, and
scleras. Light emitting diodes illuminate the eyes, and these LEDs
produce reflections off the corneal surfaces to provide critical
geometric information about the orientation of the eyeball.
• If a person is looking at a computer screen, for example, the gaze
point may be expressed in x,y screen coordinates.
11.
12. Techniques used for measuring eye movements.
1:Skin Electrodes
2:Contact Lens
2:Head Mounted
3:Remote System
13. Skin Electrodes
In this method, sensors are attached at the skin around the eyes to
measure an electric field exists when eyes rotate.
By recording small differences in the skin potential around the eye, the
position of the eye can be estimated.
it is possible to separately record horizontal and vertical movements.
Advantage:
it is a cheap, easy and invasive method of recording large eye
movements.
14. • The big advantage of this method is its ability to detect eye
movements even when the eye is closed.
15. Contact lens
A contact lens fits over corneal bulge
Provides accurate data about the nature of human eye movements
16. Head Mounted
• 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.
17. Remote System
Most practical method of eye tracking.
Uses Illuminator/eye camera.
Accurate, fast and affordable
Head still needs to stay within camera range.
21. Advantages
• Eye movement is faster than other current input media
• No training or particular coordination is required of normal users
• Can determine where the user’s interest is focused automatically
• Helpful for usability studies to understand users interact with their
environments
23. conclusion
Potentially could provide new and more effective methods of
computer-human interaction
It is amazing that eye movement-based interaction can be done
The Technology is still improving, and is “not quite there” yet –
but has an exciting future!
