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Updated: May 20, 2026

Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity
Published on: March 18, 2019
Microsaccadic efficacy and contribution to foveal and peripheral vision
Michael B McCamy1, Jorge Otero-Millan, Stephen L Macknik
1Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona 85013, USA.
Abstract:
Our eyes move constantly, even when we try to fixate our gaze. Fixational eye movements prevent and restore visual loss during fixation, yet the relative impact of each type of fixational eye movement remains controversial. For over five decades, the debate has focused on microsaccades, the fastest and largest fixational eye movements. Some recent studies have concluded that microsaccades counteract visual fading during fixation. Other studies have disputed this idea, contending that microsaccades play no significant role in vision. The disagreement stems from the lack of methods to determine the precise effects of microsaccades on vision versus those of other eye movements, as well as a lack of evidence that microsaccades are relevant to foveal vision. Here we developed a novel generalized method to determine the precise quantified contribution and efficacy of human microsaccades to restoring visibility compared with other eye movements. Our results indicate that microsaccades are the greatest eye movement contributor to the restoration of both foveal and peripheral vision during fixation. Our method to calculate the efficacy and contribution of microsaccades to perception can determine the strength of connection between any two physiological and/or perceptual events, providing a novel and powerful estimate of causal influence; thus, we anticipate wide-ranging applications in neuroscience and beyond.
Insights
Microsaccades, small, rapid eye movements, are crucial for maintaining vision during fixation. This study reveals they are the primary contributors to restoring both central and peripheral vision, resolving long-standing scientific debate.
Area of Science:
- Neuroscience
- Vision Science
- Ophthalmology
Background:
- Human eyes exhibit constant motion, known as fixational eye movements, even during attempted gaze fixation.
- The precise role of different fixational eye movements, particularly microsaccades, in preventing visual fading and maintaining vision remains a subject of scientific debate.
- Previous research has lacked methods to accurately quantify the specific impact of microsaccades on vision compared to other eye movements.
Purpose of the Study:
- To develop and apply a novel generalized method for precisely quantifying the contribution and efficacy of human microsaccades in restoring visibility during fixation.
- To compare the visual restoration capabilities of microsaccades against other types of fixational eye movements.
- To provide a robust method for estimating causal influence between physiological and perceptual events.
Main Methods:
- Development of a novel generalized quantitative method to assess eye movement efficacy.
- Comparison of the contribution of microsaccades to visual restoration against other fixational eye movements.
- Application of the method to evaluate both foveal and peripheral vision during fixation.
Main Results:
- Microsaccades were identified as the most significant contributors to restoring visibility during fixation.
- This effect was observed for both foveal (central) and peripheral vision.
- The developed method provides a powerful tool for estimating causal influence between physiological and perceptual events.
Conclusions:
- Microsaccades play a dominant role in maintaining visual perception by counteracting visual fading during fixation.
- The novel methodology offers a reliable way to assess the causal impact of specific physiological events on perception.
- This research has broad implications for neuroscience, vision science, and understanding human perception.
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