5. "yi sue.l Acu~tl' of the Astronauts
Reports by the Mercury astronauts that they were able to ob-
serve very small objects on the ground aroused considerC'ble interest
in the general matter of the visual acuity of the ~~f:tronauts. One
oi the criteria in the selection of the astronauts to begin with
was that they have e~cellent eyAsight, but it was not known whether
their high level of visual ac'",ity would be sustained during flight.
Therefore, experiments were designed to test whether any significant
change ill visual acuity could be Jl'tected during extended flights.
'!;WSl' C'xperimellts were ('~trril~d out d'lrin~ Ccmini S (R daiS) and
t;emini ., (1~ days).
An ill-flight vil'ion tester wa5 used one or more times rer day,
and tlw J'('sul ts w('re compuTed wi til preflight tests lIlau() wi th the
Silme equipment. In l1dJi tion, a test pattern was laid out on the
~round Jlear Laredo. 'rex. for observation during flight. The reader
ls referred to tIlt' original report for the details of the carefully
c-:-ntrolled cxpcr~ment~. IIhieh led to the follOWing conclusions:
Data from the inflight vision tester show
that no change was detected in the visual
performance of any 'Jf tlle foul' astronauts
who composed the crews cf Gemini 5 and Gemini
7. Results from observations of the ground
site near Laredo, Tex., confirm that the visual
performance of the astronnuts duri ng SptH'C
flight \.;as Idthin the ~tntistical runge of
the i r prefl i gh t v i stUll performunce and
JCll101lstl'Hte that laboratory viauul data can
be' combincu \.;ith l'lwirol1l11e'ntal optical uat1
to pr('dict COl'l'N~tly the limiting visual
capability of astronauts to discriminate sl1lu11
cbjeds on tll~' sllrfacl~ of the earth in tile daylight.
5. ~isu~u~ty of the Astronauts
Reports by the ~le~'cury astronauts that they were able to on-
serve very small objects on the ground aroused consider"ble interest
in the general matter of the visual acuity of the ~Etronauts. One
of the criteria in the selection of the astronauts to begin with
was that they have cJ..cellcnt ey"sight, but it. was not known whether
tlwir high level of visual ae',dty would be sustained during flight.
Therefore, experiments were designed to tcst whether any significant
change il1 visual acuity could be Jetected during extended flIghts.
T~ll'~l' C'xperimC'llts wer,' clrril'd alit d"Ling Ccm.ini S (H dai~) <.Ind
(;('mini ~ (1.1 days).
An ill-flight vi~ion tester was used one or more times pcr day,
and thL~ )'('sul ts were c:omparcd wi th preflight tests lI1ai.h~ wi th the
same equipment. In addition, a test pattern was laic! out on the
~round near Laredo, Tex. for observation durIng flight. The reader
ls referred to tlw original report for the details of the carefully
C',:-ntrollcd exper~mentfl. l/hich led to the following conclusions:
Data from the inflight vision tester show
that no change was detected in tho visual
performance of any ()f tile four astronauts
who composed the crews c1' C;emini 5 ilnd Gemini
7. Result~ from observations of the ground
5i te near I.aredo, Tex., C'onfirm that the visual
pCl'fOl'manCl' of the Ilstronnuts during splice
flight was within the Atntistical rBnge of
thei l' profl i gil t visual pertOl'1I111nCC Bnd
Jelllonstrntl' that lahoratory vi5uul data can
be combi lied \~i th l'llvironmcntal opt i cal uat1
to preJict correctly the limiting visual
cnpuhi I it~, of n~tronfluts to di~H~rillljnate small
Gb.iel't~ on til,' :;lIrfac.) of the earth in tile daylight,