Saccadic suppression

Visual perception appears continuous and stable, yet our eyes are constantly moving. One might assume we would consciously experience every jump, but no one perceives these movements or sees blur while their eyes shift. The question is: How does the brain suppress visual information during eye movements, what implications does this have for interface perception, and what evidence exists for this phenomenon?

Studies

The Bridge Experiment

Bruce Bridgeman and his colleagues conducted one of the first experiments on saccadic suppression at the University of California in 1975. Twenty-four participants sat in front of a screen and fixated on a central point. As they moved their eyes to a lateral target, the system shifted a bar on the display—either during the saccade or during fixation. The results were striking: shifts of up to 8 degrees of visual angle went completely unnoticed when they occurred during the eye movement. The same shift during fixation was immediately detected by all participants. The suppression was so powerful that objects could dramatically change position without being noticed.

Change Blindness during Saccades

Kevin O'Regan and his colleagues conducted an elegant experiment on change blindness at MIT in 1999. Thirty-two participants viewed complex scenes on a screen and were asked to detect changes. The researchers altered significant elements in the images—such as the color of a car or the disappearance of a building—either during a saccade or during stable fixation. When the change was synchronized with a saccade, only 15% of participants detected the alteration, even after repeated viewing. For changes during fixation, the detection rate was 89%. The suppression lasted an average of 47 milliseconds and began as early as 50 milliseconds before the actual eye movement. The brain prepares the suppression before the movement even starts.

Principle

Which principle for Customer Experience Design can be derived from this? The principle of saccadic suppression states that critical information should never change during probable eye movements; instead, important updates must occur exclusively during stable fixation phases. Since users are literally blind to changes during the 40-50 millisecond suppression phase, even drastic interface modifications can go completely unnoticed, leading to confusion or disorientation. This principle becomes particularly relevant for dynamic content, animations, and adaptive interfaces, where the timing of changes is crucial for perception. The principle works best with predictable gaze patterns but loses effectiveness when users are actively searching for changes or explicitly expecting them. The following guidelines demonstrate how to implement this principle in practice.

Guidelines

Updates only during stable fixation

Critical interface changes—such as price displays, error messages, or calls-to-action—should not occur during typical reading saccades. Wait until the user fixates (averaging 200-300ms between saccades) or use explicit triggers like hover or click. Animations of critical elements should last at least 100ms to overlap with the suppression phase.

Consider typical reading patterns

When reading, eyes jump in predictable patterns: 7-9 characters to the right, with occasional regressions. Position critical information so it becomes a fixation point, not a transit point. Prices, guarantees, or limits should be placed at the beginning or end of lines, where users naturally fixate. Content in the middle of lines is frequently skimmed during saccades.

Status changes maximally visible

When critical states must change (such as product availability, price adjustments, or time limits), employ additional channels: color shifts across the entire container, subtle pulsation, or a brief delay before the transition. A text-only change can be completely missed during saccades. Combine multiple visual dimensions—position AND color AND size changes—to break through the suppression phase.

Adaptive Interfaces based on gaze patterns

Advanced Implementation: Use eye-tracking or mouse-tracking as a proxy for attention. Display additional information (such as tooltips, details, or comparisons) only after stable fixation exceeding 300ms. Prevent important pop-ups from appearing during recognizable scanning patterns. This technique is particularly valuable for complex decisions—such as insurance or financial products—where users systematically compare options.