Alteration of eye movements and motion perception in microgravity

Area of Science:

• Space Medicine
• Neuroscience
• Vestibular System Research

Background:

• Spaceflight alters sensory systems, including vestibular function.
• Understanding microgravity's effects on eye movements and perception is crucial for astronaut health and mission success.

Purpose of the Study:

• To review space research findings on eye movements and perception during vestibular stimulation.
• To identify gaps in knowledge regarding vestibular adaptation to microgravity.

Main Methods:

• Review of inflight and postflight data on reflex eye movement gain.
• Analysis of responses to various vestibular stimuli (rotational, linear, optokinetic).

Main Results:

• Changes in eye movement gain are observed, particularly for pitch and roll head movements, but data are not conclusive.
• The precise relationship between eye movement gain and subjective perception of self-motion in microgravity is undetermined.

Conclusions:

• Microgravity impacts vestibular-mediated eye movements, with otolith-stimulating movements potentially most affected.
• A standardized method combining human rotation, 3D eye movement tracking, and perceptual response measurement is proposed for future research.