Eye tracking is a technology that measures and analyzes eye movements, gaze direction, and changes in pupil size. It serves as a tool for understanding how individuals visually attend to and process information in their environment. This technology provides insights into human behavior and cognitive processes by revealing what someone is looking at and for how long.
How Eye Tracking Works
Eye tracking systems use infrared light and high-resolution cameras to capture eye movements. Near-infrared light is directed towards the eye, creating reflections on both the pupil and the cornea. Camera sensors detect these reflections.
Gaze direction is often calculated using pupil-center corneal-reflection (PCCR). This technique tracks the pupil’s center relative to the corneal reflection (glint). As the eye moves, this relationship changes, allowing algorithms to estimate gaze direction. This process measures eye positions up to 1000 times per second, providing detailed data.
What Eye Tracking Tests Measure
Eye tracking tests collect data points revealing how people interact with visual stimuli. Fixations are periods when the eye remains relatively still on a specific point, lasting 100 milliseconds or more, indicating areas of visual attention and cognitive processing. Longer fixation durations can suggest deeper engagement or difficulty in understanding the content.
Saccades are the rapid, jerky eye movements that occur between fixations, shifting the fovea (the central part of the retina responsible for sharp vision) from one point to another. The sequence of fixations and saccades forms a gaze path or scanpath, illustrating the order in which a person views information. Pupil dilation (changes in pupil size) can also be measured, correlating with cognitive load, interest, or emotional responses. Time to first fixation measures how quickly an individual’s gaze lands on a particular area, indicating initial attention and the prominence of specific elements.
Applications of Eye Tracking
Eye tracking tests have applications across many fields, providing insights into human behavior. These include:
- Academic research: Used in cognitive psychology and neuroscience to study attention, perception, and memory. Also employed in developmental studies to understand visual processing evolution.
- Usability testing and user experience (UX) design: Evaluates websites, software interfaces, and product designs by showing user navigation and interaction.
- Marketing and advertising: Assesses ad effectiveness and packaging design by revealing consumer attention.
- Clinical and medical settings: Assists in assessing neurological conditions (e.g., concussions, autism spectrum disorder) and visual disorders.
- Sports training: Analyzes athlete performance and decision-making.
What to Expect During an Eye Tracking Test
During an eye tracking test, participants sit in front of a screen, with a specialized sensor device positioned either below or above it. The initial step involves a brief calibration process. This involves looking at specific points on the screen, allowing the device to learn your eye movements and map your gaze.
Once calibrated, you will be asked to perform various tasks, such as looking at images, reading text, or interacting with a digital interface. The test is non-invasive, meaning there is no physical contact with your eyes, and it is designed to be comfortable. The technology uses invisible infrared light, which does not cause distraction, ensuring a natural viewing experience.