Evening star. [volume] (Washington, D.C.) 1854-1972, 1885-06-03
Color Blindness,

Color Blindness.
RED AND GREEN MOST BOTHER THOSE WHOSE
VISION is IMPERFECT.
From Paper by DR.. George S Munson
The most frequent defect in color blindness is
the inability to distinguish red. A distinguished
professor in an English university once wore a
scarlet gown through the streets, much to the
amusement of many who saw him. On being
asked by friend what appeared to him to be
the color of this robe, he answered, pointing to
some evergreens near by, at seems to me to re-
semble those closely as possible" The next
color most frequently mistaken for some other
is green. The Importance of this defect is esti-
mated by the frequency of its occurrence III
it occurs only once in 10000 persons it is of
course of less Importance than if happening
once in 100. Men are more frequently affected
with this defect in vision than women The
defect, when 1t is congenita, as it is in most of
the cases under the observation of physicians
Is 1ncurable. 1t is sometimes induced by i'm
moderate use Of tobacco or liquor. As many as
lines OF travel are affected by this inability to
distinguish rem from green. The color blind in
case OF accident by travel on land and sea cam
not readily be detected because of the difficulty
of tracing the causes of the accident. One thus
affected cannot tell red from a green light.
but one of these lights appears darker or less
bright TO him than the other
The test OF color blindness is not how well one
can name cOlors, but how much he sees them
II two letters be drawn, one red and another
green, on background, a person who is red
blind will distinguish only the green letter and
person who is green blind would fail to dis
tinguish or see the green letter. In other words.
to the first the red color is suppressed and to
the second the green. The red blind will place
a purple or green alongside OF rose color,
supposing them all to be the same shade The
green blind will confound the blue and the
gray with the rose color. The test for an enoi-
neer Is not to name cOlors and shades of color
but TO know red as red and green as green and
to match red with red and green with green of
their various shades. Four per cent of the
10000 employees of the Pennsylvania have been
found totally color blind and ten per cent more
or less affected with this defect OF vision Five
per cent of the same were found with imperfect
hearing. In this city lives well-known an
imal painter who is entirely color blind He
selects his color, not by knowing the color it.
sell, but by reading their names on the tubes
he employs usually only black, brown and
white in his work
DR.: Jefiries, of Philadelphia, instituted a very
efncient test of color blindness by suspending
numbered skeins of worSted OF different cOlors
from a rod The standard colors OF rose. red
ana green, with all the various shades of these
colors, were numbered with the odd numbers
All otner coiors We're numbered with even num-
Ders Inc persons examined for color blind
ness were invited TO match shades OF the three
named before as the standard. and III any so
named were among those numbered with the
even numbers 1t was seen at once that they
were unable 10 distinguish coors