Eye tracking technology involves the measurement and analysis of the movement of a person’s eyes. It is widely used in various fields such as psychology, human-computer interaction, market research, and more. There are several methods and devices used for eye tracking, each with its own advantages and limitations. Here are some of the common eye tracking technologies:
- Electrooculography (EOG): EOG measures the electrical potential generated by the movement of the retina relative to the cornea. Electrodes are typically placed around the eyes to record these movements. While EOG is less accurate than other methods, it’s relatively simple and can be used for basic eye movement detection.
- Video-Based Eye Tracking: This is one of the most common methods and involves using cameras to capture images or videos of a person’s eyes. By analyzing the images, software can determine the gaze point and track eye movements. There are several techniques within this category:
- Pupil-Corneal Reflection (Pupil-CR): This method calculates the gaze point based on the corneal reflection of a light source on the surface of the eye.
- Dark-Pupil Tracking: This tracks the center of the pupil to determine gaze direction. It works well in controlled lighting conditions.
- Bright-Pupil Tracking: Similar to dark-pupil tracking, this method tracks the reflection of an infrared light source off the retina. It’s often used in eyegaze systems.
- Infrared Eye Tracking: This method uses near-infrared light to illuminate the eyes, and infrared cameras capture the reflections off the cornea and pupil. This is commonly used in head-mounted eye trackers and allows for accurate tracking in various lighting conditions.
- Remote Eye Tracking: Remote eye tracking systems use cameras to track eye movements from a distance, without requiring physical contact with the person being tracked. This is often used in usability testing, market research, and more.
- Head-Mounted Eye Tracking: These systems involve wearing a device with integrated cameras on the head. They offer high accuracy and are used in research, virtual reality, and augmented reality applications.
- Mobile Eye Tracking: This involves using smartphones or tablets equipped with front-facing cameras to track a person’s eye movements. It’s useful for studying real-world interactions with mobile devices.
- Wearable Eye Tracking: Some companies have developed wearable devices, like glasses, that incorporate eye tracking technology. These devices can be used for a variety of applications, from research to assistive technology.
- Combining Eye Tracking with Other Sensors: Eye tracking data can be combined with data from other sensors, such as accelerometers and gyroscopes, to provide more comprehensive insights into user behavior and interactions.
Eye tracking technology has applications in various fields, including psychology (studying visual attention and cognitive processes), user experience design (evaluating interface usability), marketing (assessing consumer behavior), gaming (providing more immersive experiences), and medical diagnostics (detecting neurological conditions). The choice of technology depends on factors such as accuracy requirements, study environment, and intended use cases.