Viewgraphs on effect of microgravity on visual contrast threshold during STS shuttle missions are presented. The purpose, methods, and results are discussed. The visual function tester model 2 is used

Genco, Louis V.

Oneal, Melvin R.

Task, H. Lee

English

NASA Technical Reports Server

EFFECT OF MICROGRAVITY 
ON VISUAL CONTRAST THRESHOLD 
DURING STS SHUTTLE MISSIONS 
VISUAL FUNCTION TESTER = MODEL 2 
(VFT-2) 
LT COL MELVIN Rm O'NEAL, OwDm, PhmDm 
H. LEE TASK, PhwDm 
COL LOUIS V. GENCO, OmD.9 MmSw 
https://ntrs.nasa.gov/search.jsp?R=19930019552 2020-03-17T04:40:53+00:00Z
PURPOSE (VFT-2) 
Previous contrast threshold studies, both U.S. and Soviet, 
at different test distances and may be affected by age, 
lighting, and method of target presentation 
Determine effect of microgravity on distance visual 
contrast threshold over mission duration 
Use variable contrast adjustment device under controlled 
lighting condition to obtain more precise threshold 
measurement 
Testatmultiplespatialfrequenciesandwithadditional 
target types to more completely evaluate 
i VISUAL 
HETINA LGN CORTEX 
UNIFYING NORMAL VlSlON 
/ VISUAL 
ABNORMAL VlSlON ;T STANDARDS 
I THRESHOLD AND 
SUPRATHRESHOLD 
IMPROVED 
VlSlON 
TARGET 
ACQUISITION 
AND IMAGE 
PROCESSING 
'. 
* ,', '. .. i . --. ,f' . ,.' 
- + + t +'m C 
"'y- 
\ - - - .  .- - 
ORIGINAL CONTRAST BASIC FORM . .. IDENTIFICATION DETAILS: TEXTURE +EDGES 
METHODS (VFT-2) 
SUBJECTS 
5 Flights, 12 STS Astronauts 
-- 3 subjects with no post flight data 
-- 1 uncorrected (no glasses) 
-- 1 SCL, 1 Toric-SCL 
APPARATUS 
Visual Function Tester - Model 2 (VFT-2) 
-- Small, hand-held, battery powered 
-- Three target types: 
- Square-wave gratings (detection task) 
- Disks (detection task) 
- Tribars (orientation task) 
PROCEDURE 
SAME AS VFT-1 
. 

RESULTS 
VISUAL CONTRAST THRESHOLD 
Insufficient number of subjects for report at this time 
VFT-2 manifested on STS-53 (2 astronauts) scheduled to 
fly Dec 92 
Preliminary reporting of visual psychophysical study 
may affect subsequent data and should be avoided 


Effect of microgravity on visual contrast threshold during STS Shuttle missions: Visual Function Tester-Model 2 (VFT-2)

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