Contrast Sensitivity and Eye Microtremor as Markers of Adaptation and Readaptation in a Model Experiment to Study the Influence of Gravity Changes

Abstract

Visual perception plays a crucial role in providing the brain with the information it needs to make decisions, build a picture of the world, and adapt to changing environmental conditions. Under conditions of "dry" immersion, which simulates the effects of weightlessness on the human body, contrast sensitivity and tremor eye movements were studied under changing environmental conditions. The study involved 10 volunteers (mean age 30.8±4.6 years). The contrast sensitivity of the visual system was recorded using the method of visocontrastometry. We presented the Gabor elements with a spatial frequency: 0.4; 0.8; 1.0; 3.0; 6.0 and 10.0 cycle/deg. The parameters of eye micromovements, i.e., the amplitude and frequency of eye tremor oscillations, were recorded using an optical system providing high-frequency video recording. The measurements were carried out the day before immersion in the immersion bath, on days 1, 3, 5, and 7 of “dry” immersion, as well as the next day after its completion. A change in contrast sensitivity in the range of low and high spatial frequencies, as well as in the amplitude of eye micromovements, was established. The data obtained today are a new step in the search for methods for an objective assessment of the functional state under changing environmental conditions.