Effects of visual blur on microsaccades during visual exploration

Area of Science:

• Ophthalmology
• Neuroscience
• Visual Science

Background:

• Microsaccades are small, rapid eye movements crucial for vision.
• They help counteract visual fading and optimize sampling in complex scenes.
• Microsaccade production is linked to visual task demands and retinal error.

Purpose of the Study:

• To investigate how uncorrected refractive error-induced blur affects visual search performance.
• To determine the impact of blur on microsaccade characteristics during different visual tasks.

Main Methods:

• Eye movements were recorded in 14 healthy subjects under both corrected and uncorrected refractive error conditions.
• Participants performed visual fixation, blank scene viewing, and visual search (spot the difference) tasks.
• Analysis included microsaccades, saccades, accuracy, and reaction times.

Main Results:

• Visual search performance, including correctly identified differences, was significantly lower with uncorrected refractive error.
• Microsaccade frequency decreased during visual search tasks with uncorrected refractive error.
• No significant changes in microsaccades were observed during fixation or blank scene viewing.

Conclusions:

• Visual blur from uncorrected refractive error negatively impacts visual search efficiency.
• The precision of the retinal image is critical for calibrating microsaccade amplitude during visual scanning.
• Maintaining clear vision is essential for optimal eye movement control in demanding visual tasks.