The Short Answer
Eye tracking answers one question: what do users see first?
Because what they don’t see, they can’t interact with.
The 5 Eye Tracking Metrics
Fixations
Steady gaze on one spot. Indicates information processing.
Saccades
Rapid eye movement between fixations. The eye jumps, doesn’t glide.
Dwell Time
Total time spent looking at an element. Longer = more attention (or confusion).
First Fixation
The very first thing users look at. Critical for hero sections and CTAs.
Heatmap
Aggregated gaze data across multiple users. Hot = cold.
How Eye Tracking Works
Hardware
Specialized cameras track pupil position at 60-120 Hz.
Calibration
Users look at 9 points on screen. System maps gaze to screen coordinates.
Recording
Eye position recorded alongside screen content.
Analysis
Data overlaid on screen: heatmaps, gaze plots, heatzones.
What Eye Tracking Reveals
F-Pattern
Users scan long pages in an F-shape. Top, left, then down.
Z-Pattern
Users scan simple pages in a Z-shape. Top-left to bottom-right.
Blind Spots
Users consistently miss elements in expected positions.
Banner Blindness
Users ignore anything that looks like an ad.
The Bottom Line
Eye tracking is powerful but expensive. For most teams, heatmap tools + usability testing + eye tracking theory = enough insights. Don’t skip the research, but don’t overspend either.