Westcott Color Slide Test for

Color Blindness

Created for CVCA Physicsby

Dick Heckathorn29 May 2K+4

COLOR-BLINDNESS

absolutely disqualifies a person for some vocations such

as those connected with the railroads, the navy,

color-photography

or painting.

Except in cases of an accident, color-blindness

dates from birth

and is due to a defect

in the retina of the eye

which cannot be remedied.

Color-blindness may be divided into two general classes

red-blindness and green-blindness

depending on which color

is absent in the color sense.

Sometimes both these colors are absent.

A third and rare formis the violet-blind.

Of the human raceabout 4% of males and

about one-fourth of 1% of femalesare said to be blind to

red, or green, or to both.

Attention was brought forcibly to the

danger of color-blindnessamong railway employees

by a serious accident in Sweden in 1875.

DIRECTIONS

A Westcott slide

will now be used

for testing whether

you are color-blind or not.

Take out a penciland a piece of paper. Once your instructor

begins to give directions,NO questions or discussion

will be alloweduntil the test is finished.

There is to be NO talking from now on.

TEST A

On the paper writethe number of the

sample color(s)that you thinkare similar to

(Green) Color A.

You will find very few,

if any samples

exactly like Color A.

You are to include in this list

all greens whether tending

toward the yellow,

or toward the blue.

There are manysamples of color

on the slidewhich should not be includedin any of the lists asked for.

Your instructor

will wait

until he senses

all are finished.

TEST B

As before,

write the number of

the sample color(s)

that you think are similar to Rose (Color B).

TEST C

This timewrite the number ofthe sample color(s)

that you think are similar to Rose (Color C).

How many of these numbersdo you have on your list?

For Test A

5 24 26 28 37 392 16

If you are color-blind,

whether to red or green,

you will include with the greens one or more grays, browns or roses,

and it is not uncommon for you

to include as many as

20 numbers in this list.

The presence of

any of the above

among the greens

betrays at once

that you have

a defective color sense

for either red or green.

How many of these numbers

do you have on your list?

1 13 23 4036

For Test B

The red-blind selects

indifferently roses and blues,

while the green-blind

adds greens and grays.

The tendency of the color-blind

being always to select deeper colors.

Test C was used to confirm

the results of tests A and B.

How many of these number

do you have on your list?

3 21 25 3827

For Test C

The red-blind will select the

reds, greens and browns

darker than the red.

The green-blind will add

greens and browns

lighter than the red.

Only the more marked cases

of color-blindness

are likely to show their defect

in this test.

Should this test indicate that you might have color blindness, contact your doctor for further

investigation.

That’s all folks!