individually, then both eyes together. Do not
allow the examinee to squint or tilt his head.
With the graduation of the size of the letters
advocated by Snellen, the visual acuity is
expressed according to his classical formula V =
d/D, where d is the distance at which the letters
are read, is divided by D the distance at which
the letters should be read.
Then record the
smallest line read on the chart from the 20-foot
distance as the vision; e.g., 20/20, 20/200.
When the Armed Forces Vision Tester is not
available, Jaeger cards are used to test near vision.
There are six paragraphs on each card. Each paragraph
is printed in a different size type and labeled as J-1 (the
smallest print size), J-2,..., up to J-6.
When testing with these cards, you should hold the
card at a distance of 14 to 16 inches from the examinee
and tell the examinee to read the paragraphs. Record
the visual acuity as the smallest type he can
comfortably read and record the distance (e.g., J-2 at
The distance of the card from the
examinee may be converted to centimeters,
but ensure the results of the test are also
recorded in centimeters. Consistency is the
Armed Forces Vision Tester
The Armed Forces Vision Tester (AFVT) is a
semiportable machine that has the capability to test
near and distant visual acuity, horizontal and vertical
phorias, and stereopsis (depth perception). It consists
of two rotating drums that hold illuminated slides. The
handles on the side of the machine rotate the drums to
change the slides.
A scoring key and instruction
manual are provided with the machine.
COLOR VISION TESTING
The Manual of the Medical Department requires
that all applicants for the naval service receive a color
vision test. The Navy has two methods of testing color
the Farnsworth Lantern Test
(FALANT) and the pseudoisochromatic plates (PIP).
The FALANT is the preferred test, and in many cases it
is the test prescribed by the MANMED as the only
acceptable method for testing color vision.
Farnsworth Lantern Test
The purpose of the Farnsworth Lantern Test is to
evaluate color perception. The Farnsworth Lantern is a
machine with a light source directed at the examinee.
What the examinee sees is two lights in a vertical
plane. These lights appear in two of three possible
colors, either red, green, or white, shown in varying
combinations. The examinee is asked to identify the
color combinations from top to bottom at a distance of
8 feet; the examiner rotates the drum to provide the
different combinations. The examinee must identify a
total of nine different combinations.
On the first run of nine lights, if the examinee
correctly identifies all nine, the FALANT is passed. If
the examinee incorrectly identifies any of the lights,
two additional runs of nine lights are performed
without interruption. The score is the average number
of incorrectly identified lights of the second two runs.
If the average score is 1 or less, the FALANT is passed.
If the score is 2 or more, the FALANT is failed. If the
score is 1.5, the test should be repeated after a 5-minute
break. Do not retest scores of 2 or more since this will
invalidate the test procedure.
NOTE: If examinees wear corrective lenses
for distant vision, they should wear them
during this test.
If the FALANT is not available, pseudoiso-
chromatic plates (PIP) are used to determine color
vision. Personnel so tested must be retested with the
FALANT at the first activity they report to that has a
Two tests are available, the
18-plate test and the 15-plate test, each of which
includes one demonstration plate not used for scoring.
When administering the PIP examination, you
should hold the plates 30 inches from the examinee.
Allow 2 seconds for each plate identification, and do
not allow the examinee to touch the plates. To pass the
18-plate test, the examinee must identify a minimum of
14 of the 17 test plates; for the 15-plate test, a minimum
of 10 of the 14 test plates. Record the score in block 64
of the SF 88 as PASSED PIP or FAILED PIP. Include
the number of correct responses (e.g., PASSED PIP 17
of 17 or FAILED PIP 10 of 17).
An audiogram is a record of hearing thresholds an
individual has for various sound frequencies.