Eye sensors, often found in eye trackers, work by capturing images of the eyes using specialized camera sensors that are sensitive to near-infrared light, and analyzing the reflections to determine eye movement and gaze direction. This is often based on a technique called pupil-center corneal reflection (PCCR).
Eye Tracking Technology Explained
Eye trackers utilize sophisticated technology to monitor eye movements. Here's a breakdown of how they function:
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Camera Sensors: The core of the system consists of camera sensors. These sensors are strategically positioned in front of the user to obtain a clear view of their eyes.
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Near-Infrared Light: The camera sensors are specially designed to be sensitive to near-infrared light. This type of light is typically invisible to the human eye, making the tracking process unobtrusive and comfortable for the user.
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Image Capture: The sensors work by capturing images of the eyes. These images contain crucial information needed for tracking.
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Pupil-Center Corneal Reflection (PCCR): This is a key technique used in many eye trackers. It relies on analyzing the reflections of light from the cornea (the clear front surface of the eye) and the pupil (the black center of the eye). By examining the relationship between these reflections, the system can accurately determine the user's gaze direction.
Components and Process
Here's a simple table summarizing the process:
| Step | Description |
|---|---|
| 1. Illumination | Near-infrared light is emitted towards the user's eyes. |
| 2. Reflection | The light reflects off the cornea and the pupil. |
| 3. Image Capture | The camera sensors capture images of these reflections. |
| 4. Analysis | Sophisticated algorithms analyze the images to determine the pupil center and corneal reflections, and then calculate the gaze direction. |
Applications
Eye tracking technology has various applications, including:
- Research: Used in psychology, marketing, and usability studies.
- Assistive Technology: Helps individuals with disabilities interact with computers.
- Gaming: Enhances gaming experiences by allowing players to control actions with their eyes.
