Eye tracking

Eye tracking is both a technology and a research method that records eye movement — the direction of gaze, points of focus and the path the eyes travel across a screen or object. In digital design it objectively answers the question of what a user actually looks at, in what order and for how long, rather than relying solely on self-reported claims or the designer's intuition.

How eye tracking works

The study uses a device called an eye tracker, which employs cameras and infrared light to locate the reflection off the cornea and follow the position of the pupil. From this, software calculates the exact point of gaze on the screen many times per second. The collected data is presented in several forms:

• Heatmaps — use colour to show the areas that received the most gaze.
• Gaze plots — reconstruct the order and duration of eye fixations.
• Areas of interest (AOI) — measure how much attention a specific interface element captured.

Eye tracking studies have revealed established patterns of reading web pages, such as the F-shaped layout, in which users first scan the top and left edge of the content.

Eye tracking in practice

In UX and UI design, eye tracking is used to test the usability of sites and apps: it checks whether calls to action and key messages draw the eye, where users get lost and which elements are overlooked. The findings feed design decisions, which are then verified quantitatively with A/B tests. The technology is also used in advertising research, analysis of the user journey and in gaze-controlled accessibility solutions.