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The Eyegaze System

             The Eyegaze System is a communication and control system for people with physical disabilities. The Eyegaze System is a direct-select vision-controlled communication and control system. By looking at control keys displayed on a screen, a person can synthesize speech, control his environment (lights, appliances, etc.), operate a telephone, type, operate the computer mouse and browse the internet. Eyegaze Systems are being used to write books, attend school and enhance the quality of life of people with disabilities all over the world. Eyegaze Systems are being used in homes, care facilities, hospitals, offices, and schools. 

Sophisticated image-processing software in the Eyegaze System continually analyses the video image of the eye and determines where the user is looking on the screen. Eyegaze communication is a potential porthole into current cognitive processes and communication through the direction of eyes which is faster than any other mode of human communication.


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           Imagine yourself being an intelligent, motivated, and working person in the fiercely competitive market of information technology, but just one problem you can’t use your hands. Or you can’t speak. How do you do your job? How do you stay employed? You can, because of a very good gift from computer Industry: The Eyegaze, a communication & control system you run with your eyes. It was developed in Fairfax, Virginia, by LC Technologies, Inc.

The Eyegaze System is a boon for the people with physical disabilities. It helps them to connect with the real world and other people. It provides an easy interface to operate, interact, and to perform computations. This system is mainly developed for those who lack the use of their hands or voice. Only requirements to operate the Eyegaze are control of at least one eye with good vision & ability to keep head fairly still. 

A person belonging to any age group can use this system. Mostly people suffering from diseases such as cerebral palsy, spinal cord injuries, brain injuries, Amyotrophic Lateral Sclerosis, multiple sclerosis, brainstem strokes, muscular dystrophy etc use Eyegaze systems.


The following video explains how an eyegaze system works. It shows how a person with physical disabilities can operate the system.

As a user sits in front of the Eyegaze monitor, a specialized video camera mounted below the monitor observes one of the user’s eyes. The user operates the Eyegaze System by looking at rectangular keys that are displayed on the control screen. To “press” an Eyegaze key, the user looks at the key for a specified period of time. The gaze duration required to visually activate a key, typically a fraction of a second, is adjustable. An array of menu keys and exit keys allow the user to navigate through the Eyegaze programs independently.


Working of Eyegaze System
Working of the Eyegaze System

Sophisticated image-processing software in the Eyegaze System’s computer continually analyzes the video image of the eye and determines where the user is looking on the screen. Nothing is attached to the user’s head or body.

In detail the procedure can be described as follows:

The Eyegaze System uses the pupil-center/corneal-reflection method to determine where the user is looking on the screen. An infrared-sensitive video camera, mounted beneath the System’s monitor, takes 60 pictures per second of the user’s eye. A low power, infrared light emitting diode (LED), mounted in the center of the camera’s lens illuminates the eye. The LED reflects a small bit of light off the surface of the eye’s cornea. The light also shines through the pupil and reflects off of the retina, the back surface of the eye, and causes the pupil to appear white. The bright-pupil effect enhances the camera’s image of the pupil and makes it easier for the image processing functions to locate the center of the pupil. The computer calculates the person’s gazepoint, i.e., the coordinates of where, he is looking on the screen, based on the relative positions of the pupil center and corneal reflection within the video image of the eye. Typically the Eyegaze System predicts the gazepoint with an average accuracy of a quarter inch or better.

Prior to operating the eye-tracking applications, the Eyegaze System must learn several physiological properties of a user’s eye in order to be able to project his gazepoint accurately. The system learns these properties by performing a calibration procedure. The user calibrates the system by fixing his gaze on a small yellow circle displayed on the screen and following it as it moves around the screen. The calibration procedure usually takes about 15 seconds, and the user does not need to recalibrate if he moves away from the Eyegaze System and returns later.

Menus of the Eyegaze System:        

The main menu:

The Main Menu appears on the screen as soon as the user completes a 15-second calibration procedure. The Main Menu presents a list of available Eyegaze programs as shown in the below figure.

Menus of the Eyegaze System

The user calls up the desired program by looking at the Eyegaze key next to his program choice.


VI. Menu Options:

The Phrase Program:

Phrases include Hello, goodbye, how are you? where have you been, what are you doing, talk to me, I am not well etc. Along with the speech synthesizer, provides quick communications for non-verbal users. Looking at a key causes a preprogrammed message to be spoken. The Phrases program stores up to 126 messages, which can be composed and easily changed to suit the user.

The telephone program:

The telephone program allows the user to place and receive calls. Frequently used numbers are stored in a telephone “book”. Non-verbal users may access the speech synthesizer to talk on the phone.

Telephone program in the eyegaze system
Telephone Menu

Run Second PC:

The Run Second PC program permits the Eyegaze Communication System to act as a peripheral keyboard and Mouse interface to a Windows computer. The user can run any off-the-shelf software he chooses on the second computer. He can access the Internet, and send an email by looking at keyboard and mouse control screens on the Eyegaze monitor. The programs being run are displayed on the second computer’s monitor. Typed text appears simultaneously on the Eyegaze and second PC’s screens.

Keyboard controlled screen in the eyegaze system
Keyboard controlled screen
Mouse Controlled Screen

Mouse controlled screen For children, Two new Eyegaze programs have been added to the Eyegaze System. Both run with the Second PC option. Eye Switch is a big, basic On-screen switch to run “cause & effect” software programs on a Second PC. Simple Mouse is an easy mouse control program to provide simplified access to educational software on a Second PC.

The Lights & appliances Program:

The Lights & appliances Program which includes computer-controlled switching equipment provides Eyegaze control of lights and appliances anywhere in the home or office. No special house wiring is necessary. The user turns appliances on and off by looking at a bank of switches displayed on the screen.

Paddle games & Score Four:

These are the Visually controlled Games.

Read Text Program:

The Read Text Program allows the user to select text for display and to “turn pages” with his eyes. Any ASCII format text can be loaded for the user to access. Books on floppy disk are available from Services for the Blind.


Television programs can be displayed directly on the desktop Eyegaze System screen. On-screen volume and channel controls provide independent operation. (Not available on the Portable Eyegaze System.)


Different Eyegaze systems available:

The Eyegaze system

Environment required for Eyegaze System:

           Because eye-tracking is done using infrared light.Eyegaze system must take care of light sources in the room in order to ensure the best accuracy. The Eyegaze System must be operated in an environment where there is limited to ambient infrared light. Common sources of infrared light are sunlight and incandescent light bulbs. The System makes its predictions based on the assumption that the only source of infrared light shining on the user’s eye is coming from the center of the camera. Therefore, stray sources of infrared may degrade the accuracy or prevent Eyegaze operation altogether. The System works best away from windows, and in a room lit with fluorescent or mercury-vapor lights, which are low in infrared.

Uses of an Eyegaze System:

 A. The Basic Eyegaze Can:

  1. Easier to adjust the settings for all kinds of users. (Calibration)
  2. TYPE with one of four keyboards, then print or speak. (Typewriter)
  3. TURN pages on the computer screen by looking at ‚up or ‚down. (Read Text)
  4. PLAY games, two “Paddle” games, plus Solitaire and Slot Machine.
  5. TEACH new users with simplified screens. (Teach Screens)

B. With Options The Eyegaze Can:

  1. BE at TWO SITES! The portable computer has a handle to hand-carry between two sites. Two sets of other components and cables for access to Eyegaze System at school, work or home. Dimensions 9″x5’txl7’1, weight approximately 16 lbs. (Transportable Computer)
  2. BE A KEYBOARD to a second computer to run any keyboard-controlled software, by means of the T-TAM connector. (Second Computer Mode)
  3. SPEAK 100 ‚canned phrases through a speech synthesizer, with a single glance of the eye. Phrases can be changed by caregiver or user. (Phrases)
  4. CONTROL appliances anywhere in the home or office from one Eyegaze screen. No special wiring. (Lights and Appliances)
  5. DIAL and answer a speaker phone from one screen. Phone Bookstores 16 frequently used numbers. (Telephone)



Today, the human eye-gaze can be recorded by relatively unremarkable techniques. This thesis argues that it is possible to use the eye-gaze of a computer user in the interface to aid the control of the application. Care must be taken, though, that eye-gaze tracking data is used in a sensible way, since the nature of human eye-movements is a combination of several voluntary and involuntary cognitive processes.

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