FUNCTIONAL CONDITION OF THE COSMONAUT'S VISUAL SYSTEM

IN OUTER SPACE

Leonid I. Nesteruk, PhD,

Helmholtz Institute of Eye Diseases, Moscow, Russia

Alexey B. Prokofiev, PhD, MD,

Boyan Research Inc., Moscow, Russia

And

Yuri M. Baturin, PhD, PhD,

Cosmonaut's Training Center, Zviozdny, Russia

Contact Person:  Leonid I. Nesteruk   

E-mail: ocular@mail.sitek.ru

Web: http://www.ocular.sitek.ru

PURPOSE: To study variations of the functional condition on the different levels of organisation of the visual system (VS) of the cosmonaut in the space vehicle "Soyuz" and on the board of the orbital piloted complex "Mir".

METHODS: The Cosmonaut - Researcher Yury Baturin had performed visual tests every day, except of the 1st day on the Station "Mir". Pre- and after- expedition studies also were done including one right after the landing and during 1 week of adaptation. The following visual tests were realized by means of the special PC-notebook program named "Ocular-complex":

1. Visual Acuity verification in achromatic (standard) and colored tables; 2. Luminance Sensitivity Threshold (LST) detection in the Central Part of the Visual Field; 3. Colored combinations of LST studies; 4. Rhythm's acquisition and reproduction dynamics after the complicated visual stimulation; 5. "Simple" cognitive functions investigation after the visual stimulation of varied spatial and temporal complexity.

RESULTS: It was shown for acuity of vision being stable during the experiment except of the 9^th day of the flight, when only colored combinations demonstrated the negative dynamics. The achromatic and colored LSTs was found to be increased during the flight in comparison with ones detected before and after the flight and was shown to have the different gradient in the center and paracenter of the visual field. Rhythm's acquisition and reproduction dynamics after the complicated visual stimulation demonstrated the maximum precision on the the 9^th - 10^th day of the flight, the variability of ones at the same time was also maximum, and the stability of those parameters during the flight was minimal. "Simple" cognitive functions investigation after the visual stimulation was found optimal during the flight (9^th - 10^th day) in comparison with the earth based ones. The results of the two last tests demonstrated reliable correlation during the experiment.

CONCLUSIONS: The reliable variations of the functional condition of the VS of the cosmonaut were detected before during and after the space flight by means of the "Ocular-complex" program. Five tests of the "Ocular-complex" demonstrate principally different character of the parameter's variations, what can appoint on the detection by the complex of the various properties (levels) of the VS. The data of the "Ocular-complex" tests correlate with the ones obtained on the other functional systems in the organism's adaptation during the flight. The battery of the "Ocular-complex" tests could be recommended as the basic for the evaluation of the VS's functional condition in outer space.