• 4 Camera Tracking
• Totally free head motion (96 x 96 x 50cm)
• less than 0.4 degree accuracy over the whole range of head movement
• Full range binocular – tracks both eyes with two separate cameras
• Automatic eye acquisition with face detection
• EFT (Enhanced Focusing Technology)
• Automatic calibration (5/9/13 points) for children and adults
• Bright Pupil Method – No problems with make up or glasses
• Maintains accuracy if subject tilts his head to either side
• Real Time Eye Images for observing
• Can be used with screens up to 35″ including 3D monitors
• Modular design (monitor, projection screen, real world …)

Accommodating Head Range Variation:

Unmatched Head motion volume – unlimited Freedom

The accuracy of eye trackers are typically sensitive to head motion along the camera axis. As the head moves toward the camera the predicted gaze point (if uncorrected for range) moves radially away from the camera, and as the head moves backward, the predicted gaze point moves radially in toward the camera. Typically, when a person is about 24 inches from the camera, and looking at a point toward the top of the computer screen head motions of 1.0 inch along the camera Z axis result in predicted gazepoint variations of about 0.75 inches.

The LCT Analysis System uses the patented Asymmetric Aperture Method to measure variations in the range between the camera and the cornea of the eye, and it uses the range information to minimize gazepoint tracking errors resulting from longitudinal head motions.

The EyeFollower provides the largest amount of free movement of any remote eye tracker on the market without sacrificing accuracy.

Summary:
This system offers the largest level of free head motion of any remote eyetracker on the market, operates on the largest portion of the human population, while maintaining the highest level of accuracy. We also offer a free API and do not charge any yearly licencing fees.

Superior Accuracy:
To achieve high gaze point tracking accuracy, the image processing algorithms in the LCT Analysis System explicitly accommodate several sources of gaze-point tracking error. By intelligently understanding the variables of subjects eyes, such as pupil drift and orientation we are capable of tracking the users gaze down to 0.4 degrees of accuracy.

Fully Automatic Operation:
The calibration procedure is fully automatic; no assistance from another person is required. The procedure adapts to the user speed by waiting for the user to fixate clearly on each calibration point before accepting it and moving on to the next point. The procedure accommodates interruptions from the user blinking or looking away from the computer screen. The procedure simply waits for a good fixation before moving to the next calibration point.

Fast Calibration:
The procedure to calibrate the LCT Analysis System is robust yet fast and easy to perform. The calibration procedure takes approximately 10 seconds and once the user calibrates there is no reason to re-calibrate at anytime. Our systems record not only the subjects eye perimeters but also their eyes precise location in the 3D world to accommodate all geometric variables. 

Consistency Checking:

After the original pass through the calibration points, the procedure tests that the eye was properly fixated on each point by checking that each gazepoint prediction is consistent with all the other calibration points. It retakes any calibration points that are inconsistent with other points. The procedure does not accept the full calibration until the overall gaze prediction accuracy and consistency exceed desired thresholds.

Nonlinear Gaze point Tracking Equations:

The LCT Analysis System uses nonlinear equations to predict the gazepoint accurately from the measured glint-pupil vector. The nonlinear terms account for:

• the camera axis being tilted with respect to the computer screen,
• curved computer display screens
• flattening of the corneal surface toward the edges.

Accommodating Pupil Diameter Variation:

With video eyetrackers, the center of the pupil is not directly measurable from the camera’s image of the eye. The pupil center is estimated by observing the edges of the pupil and calculating the center location from the edge measurements. Due to the fact that the pupil lies behind the corneal surface of the eye, however, a ray from the center of the physical pupil does not arrive precisely at the center of the pupil image. When the eye is looking away from the camera, the curved cornea refracts the rays from the various pupil edge points differently. Thus as pupil diameter varies concentrically about its true center, the edges in the pupil image move non concentrically around the true pupil center point, even if the true pupil center is stationary. If varying pupil diameter is not explicitly accommodated, gazepoint calculations can vary up to 0.5 inch as the pupil diameter varies between 3.5 and 7 mm. The LCT Analysis System has corneal refraction compensation logic to minimize gazepoint calculation errors resulting from varying pupil diameter.

Accommodating Glint Straddling Pupil Edge:

Many eyetrackers are prone to errors when the corneal reflection is near or straddles the edge of the pupil. Pupil edge measurements in the region of the corneal reflection are unreliable, and image intensity gradients from the pupil-iris boundary distort the corneal reflection image and result in imprecise measurement of the true corneal reflection location. The LCT Analysis System has sophisticated image processing software to locate the corneal reflection accurately when the corneal reflection straddles the pupil-iris boundary

High Reliability:

Reliability refers to the range of operational conditions under which the LCTAnalysis System is able to measure gazepoint data.

Robust Eye Recognition:

Rather than using simple brightness thresholding methods to detect the pupil and corneal reflection, the LCTAnalysis System uses sophisticated pattern recognition and hypothesis testing logic to detect the eye reliably in cluttered images. The system does not get confused by reflections off glasses, or by bright or dark facial features. The system cannot measure gaze direction if reflection from glasses is directly superimposed on the pupil and/or corneal reflection, but it is not confused by these spurious reflections. It simply reports that a “measurable eye” was not found.

Accommodating Human Eye Variations:

the LCTAnalysis System accommodates a wide variation in the eye image, such as pupil size and pupil and iris brightness and it accommodates to most glasses and contacts. The system typically tracks 90% of the human population.

The value of a natural testing environment:

Unobtrusiveness is key requirement when analyzing human behavior. LC Technologies EyeFollower systems provides users with 14 times the level of free/natural movement than any other remote eye tracker on the market today. Subjects are not required to wear any device or be constrained to a viewing “box”. Operating this system is as easy as sitting in front of the device and allowing users to behave as they normally would. Incorporate eye tracking into your testing process to get a uniquely objective insight into user decisions and physiology. An unobtrusive eye tracker does not interfere with the participant‘s natural mental processes.

Superior Accuracy:
To achieve high gazepoint tracking accuracy, the image processing algorithms obtain very high resolution images of the eyes resulting in less than 0.4 degrees of angular error from the eye.

High Reliability:
Reliability refers to the range of operational conditions under which the EAS Binocular is able to measure gazepoint data.

• Dark and bright environments.
• Operates on 90% of the human population!

Accommodating Human Eye Variations:
The EAS Binocular accommodates a wide variation in the eye image, such as pupil size and pupil and iris brightness and it accommodates to most glasses and contacts. The system typically tracks 90% of the human population.

• Binocular Remote Eye Tracking
• High Accuracy less than 0.4 degree
• 10 sec Fully Automated Calibration
• Data streams of left and right eye

Fast Calibration:

Calibrating the EAS Monocular is fast and easy to perform. The calibration procedure takes approximately 10 seconds and only need to be conducted once. the EAS Monocular system also has the capability of remembering the last subject to use the devise enabling no further calibration procedures.

Superior Accuracy:

To achieve high gazepoint tracking accuracy, the image processing algorithms obtain very high resolution images of the eyes resulting in less than 0.4 degrees of angular error from the eye.

High Reliability:

Reliability refers to the range of operational conditions under which the EAS Monocular is able to measure gazepoint data.

• Dark and bright environments.
• Operates on 90% of the human population!

Accommodating Human Eye Variations:

The EAS Monocular accommodates a wide variation in the eye image, such as pupil size and pupil and iris brightness and it accommodates to most glasses and contacts. The system typically tracks 90% of the human population.

• monocular Remote Eye Tracking
• High Accuracy less than 0.4 degree
• 15 sec Fully Automated Calibration
• Data stream of eye