Milford chronicle., 1960-07-01
What Causes
Color Blindness
By DOROTHY v. wHIPPLE, N. D.
AP Ne~sseatures

AP Ne~sfeatures
Roger was color blind, but no.
body knew II, least Of all Roger.
Roger didn't complain, nothing
hurt, nothing about him seemed
strange. The way he saw the world
was what he imagined everybody
else saw-the way the world was,
he. thought.
When he was a little chap, If his
socks were not carefully paired up
In his drawer, he often picked out
a red one and a black one 10 wear
together, or a green one and a tan
one. Roger was oblivious OF dirt
on his hands. and a high water
mark around his wrists left him
completely uninterested. But after
all, thought his parents, these are
the ways OF small boys, Roger
called the sky blue and he seem
ed especially fond of bright yellow.
Nobody worried about how the
world looked to Roger.
Then one day when Roger was
almost 10 years old he was study
ing geography in school. The teach
er had q big map Of the United
States, each state colored in bright
clear colors. She gave the chill
dren test, asked them to write
down the name OF each state col
ored red and make some remark
about It, what were some Of the
cities In 1t, what industries IL had,
etc. She waited a while. then ask
ed them to pick out the green
states. Roger wasn't finished with
the red states. half the ones on the
map looked "red" to him.
Mrs. Peters watched Roger and
at noontine that day she called
him UP to her desk and asked him
to help her straighten out a pile
Of color paper she had carefully
mixed up. Roger accurately put the
blue ones in one pile, the yellow in
another. but the greens, the reds,
the grays, the tans, all went to-
gether.
Alert Teacher
That evening Mrs. Peters phoned
Rogers mother, told her what had
happened and suggested she take
him to an eye doctor and have him
tested.
Sure enough Roger was color
blind--Roger could see some col
ors but not all A good many things
began to fit into place for his mo-
ther.
Color blindness Is a hereditary
condition in almost all cases. Once
in great while, color vision will
be lost through disease or the over
use of certain drugs but the vast
majority of color blind people are
born that way.
Color blindness Is inherited in
a peculiar way. Suppose a man Is
color blind. He passes the possi-
bility for this condition to his
daughters, but they are not color
blind. However, these girls can
pass II on their sons who may real
ly be color blind. The sons of the
original color blind man are free
OF the condition. Thus, color blind
ness is inherited by boys from the
maternal grandfather. Girls only
become color blind IL both the ma
ternal and paternal grandmother
skips one generation.
There are many more color blind
men than women. In the United
States there are about 71h million
color blind men and only about a
tenth as many women.
Different Kinds
All kinds of color blindness are
not alike.
Normal people see the three pri-
mary colors-red. yellow and blue,
and can therefore see all other
colors which are combinations OF
the primary three. Normal people
are called trichromate
People who can see only two
colors are dichromate. They see
yellow and blue but red Is the
same as black to them. All colors
with red In them produce shades OF
black. Green. though made from
yellow and blue. also looks similar
to black to many dichromates. This
is the most frequent kind of color
blindness and the one Roger had.
Then there Is a small group OF
color blind people who see only
one color-they are monochromate
There is also a very small grouT
OF color blind people who appar'
emily see no color at all. They are
achrOmate.
No Cure
Color blindness cannot be cured
The special cells on the retina (tht
cone cells) just aren't there anC
there Is no way to put them there
These cells are not present a.