I) 1:AAAM-90/9 Evaluation of Functional Color

Vision Requirements and Current

A, ,,, ,:vIJ ,iJ.. Color Vision Screening Tests for

b 01, ?,,, ,59 Air Traffic Control Specialists

-lcnry W. Mertens, Ph.D.

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September 1990

DTIC<

< Final RcpoS ELECT E

This document is available to public through

the National Techtcai pnfur blto Service,

Springfield, Virginia 22161.

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NOTICE

This document is disseminated under the sponsorship of

the U.S. Department of Transportation in the interest of

information exchange. The United St;' es Government

assumes no liability for the contents or use thereof.

Lai~
Technical Report Documentation Page

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.

DOT/FAA/AM-90/9

4. Title and Subtitle 5. Report Date

Evaluation of Functional Color Vision Requirements August 1990

and Current Color Vision Screening Tests for Air 6. Performing Organ zation Code

Traffic Control Specialists

7. Autho,'s) 8. Performing Organ,zation Report No. 7. Author! s!

Henry W. Mertens

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS)

FAA Civil Aeromedical Institute

P.O. Box 25082 11. Contract or Grant No.

Oklahoma City, OK 73125 13. Type of Report and Period Covered

12. Sponsoring Agency Name and Address

Office of Aviation Medicine

Federal Aviation Administration

800 Independence Avenue, S.W. 14. Sponsoring Agency Code

Washington, D.C. 20591

15 Supplementary Notes

This work was performed under task AM-C-88/89-HRR-107

16. Abstract

An experiment was conducted to evaluate the relation of type and degree

of color vision deficiency and aeromedical color vision screening test

scores to performance of color-dependent tasks of Air Traffic Control

Specialists. The subjects included 37 normal trichromats of which 6

had mild color abnormalities. Those subjects with color vision

deficiency included 18 simple anomalous trichromats, 22 extreme

anomalous trichromats, and 31 dichromats; both protan and deutan types

were included. Simulations of ATC color tasks concerned color coding

in flight progress strips used at en route centers. color weather radar

systems used at flight service stations and en route centers, and the

Aviation Signal Light indicator light and aircraft lights as pertinent

to ATC tower operations. Errors were rare among normals and those with

mild color abnormalities in simulated normal operating conditions.

Error frequency in the simulated ATC tasks was significantly higher

among simple anomalous trichromats, and those with more severe

deficiencies. The aeromedical screening tests were generally

acceptable in terms of selecting individuals that did not make errors

on the ATC tasks. These findings support the requirement that air

traffic control personnel be normal trichromats. Recommendations for

improvement of job-related color vision screening are discussed.

17. Key Words 18. Di stribution Statement/ '

Air Traffic Controllers Document is available to the public

Color Vision Standards through the National Technical

Performance Tests i Information Service, Springfield,

Color Vision Tests Virginia 22161.

19. Securty Closs,f. tof this report / 20. Secur,y Classi,. of th, s page' 21. No. of Piges 22 Price

Unclnq fed Unclassified 27

Form DOT F 1700.7 8-72 Reproduction of completed page authorized
ACKNOWLEDGEMENTS

The author wishes to acknowledge the contributions of Linda

Matthews who organized the testing of subjects. Linda along

with Clara Williams, Sandra Miller, and LaDonna Moore also

assisted in data collection and data analysis. Patsy Fowler

assisted in assembly of testing materials. Many volunteers

were obtained from military and civilian personnel working at

Tinker Air Force Base due to the support and assistance of the

offices of the Base Commander and Tinker Hospital in

soliciting volunteers. We would particularly like to thank Lt.

Col. Richard Baldwin and Lt. Col. Roger Miller for their help.

A-ccession For

UTI-S GRA&I

DTIC TAB U'-,nnnounced

justificatiorh.

By

pistribution/

AvailabilitY Codes

IAvail and/or

Milst Special

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CONTENTS

In trodu ction ....................................................................................................... I

M eth ods ....................................................................................................... 2

Results and D iscussion .................................................................................... 6

C onclusions ..................................................................................................... 8

R eferen ces ..................................................................................................... 10

LIST OF TABLES AND FIGURES

Appendix A

Table 1: Color Vision Tests Accepted by the FAA for Airman Certification ......... Al

Table 2: Number of Subjects Passing or Failing Four Simulated ATCS Color Tasks

as a Function of Color Vision Deficiency ......................................... A2

Table 3: Number of Subjects Passing or Failing Simulated ATCS Color Tasks as a

Function of Color Vision Deficiency and Adverse Viewing Conditions.. A3

Table 4: Errors on Simulated ATCS Color Tasks as a Function of Color Vision

D eficiency ...................................................................................... A4

Table 5: Validity of Color Vision Selection Tests for Prediction of Overall

Perform ance .................................................................................. A5

Table 6: Validity of Aeromedical Color Vision Screening Tests for Prediction of

Performance on the FPS Test ....................................................... A6

Table 7: Validity of Color Vision Selection Tests for Prediction of Performance on

the Flight Progress Strips Subtest Given Under Both Normal and Low

Illum ination ................................................................................... A7

Table 8: Validity of Color Vision Selection Tests for Prediction of Performance

on Tests Radar-L and Radar-S ........................................................ A8

Table 9: Validity of Color Vision Selection Tests for Prediction of Performance

on the Aircraft Lights Test ............................................................. A9

Table 10: Validity of color Vision Selection Tests for Prediction of Performance

on the Aviation Signal Light Indicator Test ................................... A10

Appendix B

Figure 1: Flight Progress Strips Errors as a Function of Color Vision Deficiency.

......................................................................................................... B I

Figure 2: Radar Errors as a Function of Type of Color Vision Deficiency. and

Target Size ........................................................................................ B2

v/v1
EVALUATION OF FUNCTIONAL COLOR VISION REQUIREMENTS

AND CURRENT COLOR VISION SCREENING TESTS FOR

AIR TRAFFIC CONTROL SPECIALISTS

INTRODUCTION

Applicants for Air Traffic Control Specialist (ATCS) Jobs in en route center, terminal, and

Flight Service Stations (FSS) of the Federal Aviation Administration are required to have

normal color vision (Office of Personnel Management, U.S. Government) because a number

of ATCS tasks involve critical color-coded information and, therefore, "involve the

discrimination of color for safe performance" (Adams and Tague, 1985).

Previous research by Adams and Tague (1985) found that protanopes. a group with severe

color vision deficiency, made errors on simulated ATCS color tasks, but normal

trichromats made no errors. Kuyk, Veres, Lahey, and Clark (1986, 1987) showed similar

deficits in performance of simulated ATCS color tasks by deutan and protan types with

moderate and severe levels of deficiency. These studies were consistent in finding inaccurate

ATCS color task performance by color deficients and, therefore, suggest the need for an

ATCS color vision standard. Additional research is desirable, therefore, to clarify the level

of color vision ability required for accurate color discrimination performance in ATCS

tasks, and to evaluate the validity of current color vision tests used to screen ATCS

personnel.

The following ATCS tasks involving color-coded information were identified and used in

previous research (Adams and Tague, 1985; Pickrel and Convey, 1983), and Job analysis

(Lahey, Veres, Kuyk, Clark, and Smith, 1984a, 1984b):

(1) Reading of red and black printing and red and black (or blue) handwriting on flight

progress strips used by ATCSs at en route facilities.

(2) Scanning of color weather radar displays at en route centers and FSS facilities.

Red, yellow, and green colors indicate different weather levels.

(3) Identifying aircraft and their direction of flight at night from the ATC tower while

they are in the air and on the ground, based on identification of red, green, and white

navigation lights.

(4) Identifying the color of the Aviation Signal Light (ASL) indicator that gives the ATCS

visual feedback concerning the signal color (red, green, or white) that is presented to direct

an aircraft or ground vehicle when radio communication fails or is not available.

(5) Identifying aircraft in daytime ATC tower operations by color of aircraft or its

markings.

(6) Reading of a variety of color-coded charts at all types of facilities.

(7) Selecting the appropriate colored indicator lights, keys, switches, and buttons at all

types of facilities.

The flight strips, weather radar, aircraft navigation lights, and ASL indicator tasks

involve color as a primary, non-redundant cue. Errors in color identification/discrimination in those tasks have the potential to place pilots, passengers, and their

aircraft in danger. Tasks 5 through 7 typically involve color coding as a redundant cue of

secondary importance, with primary cues such as symbol/object position, shape, alphanumerics, etc. conveying the same information. Impaired color discrimination would be most

likely to affect 'fficiency of performance rather than accuracy in tasks 5 through 7.

Decreased efficiency in time-limited situations, however, has the potential to lead to error.

1
This study was performed to determine the relation of errors in performance of simulated

ATCS color tasks to type and degree of color vision deficiency in order to evaluate the level

of color vision ability required In ATCS personnel. The simulations all involved the actual

color materials from the ATCS tasks, or used materials with characteristics determined to

be equivalent through spectroradiometric and colorimetric measurements. The relation of

performance on color vision tests currently accepted by the FAA for aeromedical screening

to performance of ATCS Tasks 1 through 4 was studied to evaluate the validity of the

clinical tests in current use for ATCS screening. The performance on flight strips and radar

tasks were studied under both average conditions, and difficult observation conditions that

have been observed in the field, i.e., low illumination of flight strip materials and small

weather radar targets as observed by Adams and Tague (1985) and Lahey, et al. (1984b). Time

limltations, dte to the la-ge number of tests required for this study, prevented inclusion of

all ATCS tasks. ATCS Tasks 1 through 4, as listed above, were selected for study because of

their frequent and consistent involvement of color as a primary task cue in safety-critical

air traffic control situations.

METHODS

Subjects.

Subjects for this study included 37 normal trichromats (23 males and 14 females) with a

mean age of 31.4 yrs and a standard deviation of 7.4 yrs and 71 anomalous trichromats and

dichromats (67 males and 4 females) with a mean age of 32.3 yrs and a standard deviation

of 9.7 yrs. All subjects had at least 20/30 visual acuity in both near and distant vision with

the OPTEC 2000 vision tester. Subjects with color vision deficiency were solicited through

advertisements in newsletters at Tinker Air Force Base and local newspapers of the

Oklahoma City metropolitan area. All subjects were paid an hourly wage.

Diagnostic Color Vision Tests.

The principle diagnostic instrument was the Nagel Type I anomaloscope (SchmidtHaensch). The anomaloscope is generally recognized as the best instrument for

differentiation of normal trichromats from individuals with "red-green" color vision

deficiencies, for differentiation of protan and deutan types among the red-green deficients,

and also recommended for diagnosis and differentiation of level of deficiency (i.e. simple

anomalous, extreme anomalous, and dichromats, in order of severity) by the NRC-NAS

Committee on Vision (1981). Other tests were given to corroborate diagnoses of red-green

color vision deficiencies and to detect and diagnose the rare "blue-yellow" deficiencies that

the Nagel anomaloscope does not detect.

The anomaloscope testing procedure described by Steen, Collins, and Lewis, (1974) was

used to obtain matches for both "neutral" and "chromatic" adaptation conditions. The

anomaloscope diagnostic classification procedure used was that described and recommended

by the NRC-NAS Committee on Vision (1981). This procedure bases diagnoses primarily on

measurements obtained under chromatic adaptation (i.e., matches obtained after the

observing the anomaloscope stimulus for at least 20 s). The classifications obtained are

listed in ascending order of severity:

Normal (n=31). These individuals comprise the majority of normal trichromats and have

a high level of color discrimination ability.

Minor (Mild) color abnormality fn=6). This classification contains those normal

trichromats called "deviant normal trichromats" and "weak normal trichromats." The

anomaloscope color matching behavior of normal trichromats varies by a relatively small

amount, but it does vary. These subgroups of normal trichromats may be thought of as

representing the "tails" of either the distribution for the matching range size (the "weak"

normal trichromats) or the distribution for matching range midpoint (the "deviant" normal

2
trichromats). Some of these individuals may show a very slight reduction in color

discrimination ability.

Simple anomalous trichromats. The simple anomalous trichromats are the "mildest" of

inherited red-green color vision deficiencies. They were separated into simple

protanomalous (n=5) and simple deuteranomalous (n=13). These individuals may have

moderate impairment of color discrimination ability.

Extreme anomalous trichromats. These color deficients were separated into extreme

protanomalous (n=5) and extreme deuteranomalous (n=17). These individuals have severe

impairment. The extreme protanomalous are also distinguished by having reduced

sensitivity to long wavelength (red) light.

Dichromats. Dichromats were similarly separated into protan and deutan groups called

protanopes (n= 11) and deuteranopes (n=20). respectively. All dichromats have severe color

deficiencies and protanopes, like the extreme protanomalous. have reduced sensitivity to

long wavelengths while deuteranopes do not.

Several other tests were used to obtain additional diagnostic information. The

Farnsworth Dichotomous Test for Color Blindness Panel D-15 provided information to

support differentiation between protan, deutan, and tritan types. The Farnsworth F2 Plate

and AOC-HRR were other tests providing information to support identification of tritan

diagnoses. Those tests have been described by others (NRC-NAS Committee on Vision. 1981:

Pokorny. Smith. Verriest, and Pinckers, 1979).

ATCS Color Tasks.

Flight Progress Strip (FPS) Test. The FPS test was similar to tests used in previous

research by Adams and Tague (1985). It required identification of colors in color-coded

computer printing or hand-writing on FPSs as used at en route centers. Subjects responded

by identifying color of computer printing (103 items) and hand writing (76 items) as red or

black (blue). Since blue is permitted to be used instead of black, a small number of blue

items were included. FPS materials were obtained from the Ft. Worth (Texas) en route

center. There was no time limit for responding and performance was assessed in terms of

number of errors and pass-fail; the failure criterion was any error. The incident

illumination level was 59 lux, an average workstation illumination measured at the Ft.

Worth en route center.

Flight Progress Strip Test-Low Illumination (FPS-L. This test utilized a subset of 38 of

the hand-written items from the above test that were presented a second time under a lower,

14 lux incident illumination level. In subsequent discussion, data concerning testing at the

normal 59 lux level with these items is referred to as the FPS-N test. The low illumination

level was selected to be marginal for normals based on preliminary measurements, but was

slightly higher than the lowest level (8.4 lux) found at an en route center that was reported

by Adams and Tague (1985). There was no time limit for responding, and performance was

assessed in terms of total errors and pass-fail; the failure criterion was any error.

Color Weather Radar Test - Large Targets (Radar-L. This test involved identification of

seven colors including the six colors of the FAA weather radar color code that represent six

different levels of precipitation, and "black," representing background or no precipitation

detected. The weather radar color code involves two shades each of red, yellow, and green.

The characteristics of display colors, 1931 CIE chromaticity coordinates x and y and

luminance (L=candelas per square meter), were: (i) light green, x=.308, y=.574, L=48.3; (ii)

dark green, x=.314, y.563, L=25.5; (ii) light yellow, x=.420, y=.495, L=65.3; (iv) dark yellow,

x=.423. y=.488, L=34.3; (v) light red, x=.598, y=.357, L=18.6; (vi) dark red, x=-.575, y=.361.

L= 11.0; and (vii) black, x=.385, y=.402, L=2.6. The display color measurements were made

with the same ambient illumination that was used during testing. The display colors and

that 118 lux ambient illumination level were similar to measurements obtained at the

3
McAlester (Oklahoma) FSS. The display was viewed by the subject at a distance of 71 cm. On

every trial, a bar showing the colors of all six precipitation levels in order of magnitude was

located 7 degrees above the center of the target. Each color segment in the bar subtended 0.5

degrees vertically and 1.3 degrees horizontally. The radar task required identifying of the

color of a 0.5 degree square target that was located at the center of a 4 degree square

background. All possible combinations of target/background colors were used to discourage

guessing, but only the 12 combinations most commonly used in radar and which represent

precipitation levels were used for test trials and scored. There was no time limit for

responding. Following a response, there was a 5-s delay before presentation of the next

stimulus. Any error caused failure of the test. Total errors were also counted.

Color Weather Radar Test-Small Targets (Radar-S). This task was identical to Radar-L,

with the exception that targets were smaller, subtending approximately 0.1 degree. The 0.5

degree target size of Radar-L was chosen to be sufficiently large that color discrimination of

individuals with normal color vision would not be adversely affected by target size. With the

0.1 deg size, somewhat decreased discrimination ability for colors on the red-green axis

would be expected. Discussions with Flight Service Specialists and meteorologists working

at FAA facilities indicated that identification of the color of very small weather radar

targets can be important. The 0. 1 degree target size was similar to the size of small targets

seen on several weather radar displays at FSS and en route centers and is approximately 4 x 4 pixels in size on the Tektronix 4125 color graphics work station used to present the

weather radar tasks. The monitor, 38.3 cm on the diagonal, had a resolution of 1280 x 1024

pixels. Lahey, et al. (1984a) also selected 0.1 deg as a small target size relevant to ATCS color

tasks.

Aircraft Lights Test. Ten pairs of lights simulating aircraft navigation lights were

projected onto a white screen in a nearly dark room. The ambient illumination of the

screen was 1.07 lux, the recommended maximum level for interior incident illumination on

tower cab windows (Illumination Engineering Society, 1972). Kodak Wratten Filters 26 and

58 were mounted over small holes in slides to simulate red and green aircraft navigation

lights. White navigation lights were simulated by using no filter. Intensity of lights was

varied with neutral density Wratten filters to ensure that color could not be associated with

brightness. Colors of simulated aircraft lights had the following approximate chromaticity

coordinates: red, x=.693, y=.307; green, x=.269, y=.683; and white, x=.460, y=.417. Although

this task was similar to the aircraft lights test of Adams and Tague (1985) in terms of target

colors, the angular subtense of simulated aircraft light was smaller. 1.4 min of arc, and the

two lights of each pair were separated vertically by 21 min of arc. The target colors met

current standards of the International Civil Aviation Organization (1988) for aircraft

navigation light colors. The criterion for failure of this test was any error.

Aviation Signal Light (ASL Test. The subject identified signal colors as reflected in the

indicator (bezel) on top of an ASL. Six signals were observed as the subject sighted the ASL

out of a third floor, north window at the sky. The signals were regulated by an experimenter

with controls shielded from the subject's view. Signals were of 5-s duration, and intervals

between signals were 3 min. The ASL signal colors (red, green, and white) were presented

randomly, with the restriction that each color be presented at least once during the six

trials. This test was administered between the hours of 10:00 am and 3:00 pm with sky

conditions varying from clear to heavily overcast. Any error constituted failure of the task.

Aeromedical Color Vision Screening Tests.

All aeromedical color vision screening tests currently known to be in use by Aviation

Medical Examiners (AMEs) for the initial medical examinations of ATCSs and pilots were

evaluated. These tests can be grouped into three categories; nine pseudolsochromatic plate

tests, three lantern tests, and four vision tester measurements and are listed in Table 1

(Appendix Al) with their First Class disposition criteria (FAA Aviation Medical Examiner's

Guide 1980). The Class I criteria are intended to select normal trichromats.

4
Pseudoisochromataic Plate Tests. The 14-, 16-, and 24-plate Ishihara tests all involve

subsets of plates from the 38-plate Ishihara test. Only the 14-plate and 38-plate Ishihara

tests were administered. Scores for the 16- and 24-plate tests were computed based on

responses to appropriate subsets of plates of the 38-plate test. It is assumed that any

differences between the plates of this simulation and the actual plates of those tests are

minor and would be similar to different printings of the same plate. Macbeth lamps was

used to illuminate all plate tests, with all other lighting extinguished during testing. All

screening tests were administered according to manufacturer's directions.

Lantern Tests. The Farnsworth Lantern test was developed by the U. S. Navy and is

currently used for aeromedical screening by both the Navy, and the U. S. Air Force. The

Farnsworth Lantern test was given in a normally lighted room, according to directions. The

U.S Air Force's School of Aviation Medicine Color Threshold Tester (SAM-CTT) was given,

but those data are not included in this report since its use has recently been discontinued.

The Edridge-Green Lantern test was not given because its use is rare and there are no known

standard procedures for test administration.

Multifunction Vision Testers. Several multifunction vision instruments include color

vision tests accepted by the FAA and all involve photographic reproductions, prints or

positive transparencies, of pseudoisochromatic plates. The Titmus, Titmus II, and OPTEC

2000 vision testers all involve positive color transparencies that are reproductions of

Ishihara test plates. Each of these tests was given in a different testing room at a different

time and was given in a dimly-lit room. The Keystone test involves photographs of six

plates that were developed specifically for that test. The Keystone test was illuminated using

only that instrument's lamp: room lights were turned out.

Three-test Battery for ATCS Aolicants That Fail Clinical Tests. The Three-test Battery is

used by the FAA Office of Aviation Medicine to test ATCS applicants that fail the color

vision test given during their initial aeromedical examination. The Three-test Battery is

normally administered at offices of regional flight surgeons. The battery includes the

Dvorine plate test, the Farnsworth D-15 test (both used with special disposition criteria

given below) and the Air Traffic Controllers Functional Color Perception Test (FCPT)

(Pickrel and Convey, 1983; Convey, 1985). If an applicant passes two of the three tests

she/he is considered to pass the ATCS medical color vision standard that requires normal

color vision. The Dvorine test is also one of the FAA-accepted tests used by AMEs, but is

used in the battery with a different, less strict failure criterion: failure with 5 or more,

rather than 3 or more errors. The D-15 test includes 15 numbered, colored chips that are

arranged in order of color by the subject. It is scored by classifying errors in two categories:

major errors and minor errors. Major errors of arrangement scored two points and involved

placing two chips next to each other that are separated by three or more steps when placed

in the correct order, while minor errors (of lesser magnitude) scored one point. A total error

score of 7 or more is considered as failing on th( D- 15 test. The battery's scoring criteria for

Dvorine and procedure for scoring the D-15 tests are based on recommendations of Lahey, et

al. (1984a). The FCPT is in book form with subtests that depict aircraft navigation lights

and exterior colors, color weather radar, and color-coded aviation charts. The FCPT was

validated using the AOC (15-plate) test as the criterion (Pickrel and Convey, 1983). All three

tests were illuminated with a Macbeth Easel Lamp in an otherwise dark room.

Procedure.

The simulated ATCS color tasks, diagnostic tests, and screening tests were administered

at four testing stations, each supervised by a laboratory technician. All anomaloscope

testing was performed by the author. The tests at each station took approximately 45 min to

administer. The testing of each subject was performed in two, 2-hour sessions separated by a

1-hour lunch break or given on successive days. Within each session, the two 45-min testing

periods were separated by a 15-min break. Since the OPTEC 2000, Titmus, and Tltmus II

involved reproductions of the same set of six Ishihara plates, each of those tests was placed

5
at a different testing station to separate them in time and by administrations of several

other tests.

RESULTS AND DISCUSSION

Relation of ATCS Color Task Performance to Color Vision Deilciency.

In air traffic control work, an error in one of the ATCS color tasks studied has the

potential to place people and aircraft in jeopardy. The tasks were, therefore, scored on a

pass/fail basis with failure contingent on the occurrence of any error. The number of

subjects passing and failing, as a function of type and degree of color vision deficiency, is

presented in Table 2 (Appendix A2). for the FPS task, the Radar-L task, the Aircraft Lights

task. and the ASL task, all of which involve simulation of normal ATCS operating

situations. The FPS task is the most important of those tasks due to the high frequency

with which the discrimination of red and black must be performed in a working day in

combination with the criticality of errors. Eiror was rare among normal trichromats

(Nomal or Mild diagnosis). One normal trichromat made one error on the Radar-L task, but

normal trichromats made no errors on the FPS task with normal illumination, the Aircraft

Lights task. or the ASL task. In contrast, many simple anomalous trichromats, extreme

anomalous trichromats, and dichromats made errors in all tasks involving normal

operating conditions. The deuteranomalous groups tended to pass more often than the

protanomalous in the Radar-L task and th," ASL task.

Table 2 (Appendix A2) also contains an overall pass/fail score. Any error on any of the

four tasks caused failure of the overall score. Only one normal trichromat failed: the

individual that made an error on the Radar task. In contrast, only one individual from the

anomalous trichromat or dichromat groups failed to make any errors on any task.

Performance under normal and marginal conditions on either the flight strip or radar

task is compared in Table 3 (Appendix A3). Under low (14 lux) illumination in the FPS-L

task. 92% of normals made no errors, while 94% of anomalous trichromats and dlchromats

failed. In the Radar-S task. when target size was small, 73% of normal trichromats made no

errors, while 99% of anomalous trichromats and dichromats did make errors. The

probability of a color discrimination error is much higher among anomalous trichromats

and dichromats than in normal trichromats under marginal/difficult viewing conditions as

well as normal viewing conditions.

The mean number of errors and 95% confidence intervals for the mean are shown for

each of the four tasks in normal conditions in Table 4 (Appendix A4). as a function of degree

of color vision deficiency. Confidence intervals are presented for comparison of means for

deficients and normal trichromats. The low, often zero variance among normal trichromats

makes analysi, of variance inappropriate for comparison of these sample means (Box,

1954). The confidence intervals for means of simple tritanomalous, extreme tritanomalous

and dichromat groups do not include the means for normal trichromat groups in any task.

These data again indicate that the probability of error is higher among anomalous

trichromats and dichromats than among normal trichromats on all four simulated ATCS

tasks.

Comparison of the relative frequency of failing among protanomalous and

deuteranomalous subjects shown in Tables 2 and 3 revealed a higher proportion failing

among the protanomalous in the Radar-L task and the ASL task. In the case of the Radar-S

task, the probability of failing was high in both protans and deutans. The performance of

protans and deutans was also compared in terms of mean errors on all tasks. Analysis of

variance was used to evaluate differences in error scores as a function of degree of color

vision deficiency among protans and deutans; normal trichromats were excluded from the

analysis. Deutans made significantly fewer errors on the average than protans in the FPS

and Radar tasks, but not in Aircraft Lights or ASL tasks. The data are shown for the FPS

tasks in Figure 1 (Appendix BI) and the Radar tasks in Figure 2 (Appendix B2). For the FPS

6
data. the main effects of type of deficiency, protan vs. deutan (F=21.87: df=1.107;p<.001),

degree of deficiency (F=20.70: df=2,107; p<.001). and illumination level (F=27.13;

df=l.107:p<.001) were statistically significant. The interaction of illumination level with

type and degree was also significant (F=5.03; df= 2,107;p<.01), indicating that the significant

difference between deutans and protans occurred only among the extreme anomalous and

dichromats, not among the simple anomalous. In the case of the radar tsks, the main

effects of type (F=5.15; df= l0 7 ;p<.05), degree (F=10.07 df=2,107:p<.001), and target size

(F=96.13; df= 1,107;p<.001) were again statistically significant, but no significant

interactions were observed.

Validity of Aeromedical Color Vision Screening Tests.

The validities of color vision tests currently in use for aeronedical screening of ATCS

personnel were evaluated regarding prediction of pass/fail performance on the ATCS color

tasks. The validity of 6creening tests was also compared with the validity of an

anomaloscope as a predictor of performance. Cohen's Kappa (Cohen, 1960), an index of

agreement, was used to assess the validity of the color vision screening tests as

recommended by the NAS-NRC Committee on Vision (1981). The index can be interpreted as

the percentage agreement between test and criterion variable, with correction for chance.

The four ATCS co. r tasks involving normal and difficult color task situations were used as

the criteria for assessing the screening tests. That is, the four ATCS color tasks were used as

samples of critical ATCS work behaviors against which the color vision tests were validated

as personnel selection criteria. These data on validity are given in Tables 6, 7, 8, 9. and 10

(Appendix A). Validities given in Table 5 involve the overall pass/fail performance index

discussed above. Failure of any test among the FPS, Radar-L, Aircraft Lights, and ASL tests,

the tests performed under normal conditions, caused failure in the overall performance

index. In addition to those simulations that represei.t common conditions in ATCS tasks,

validities are also given for prediction of performance in the FPS task under low

illumination (FPS-L) and in the Radar task with smaller target sizes (Radar-S). less common

conditions, but still within the range of conditions that could occur in those ATCS tasks. In

addition to validities, each table lists the miss and false alarm rates for each test. Miss rate

is the probability of passing the test, given failure on the criterion ATCS color task. The

false alarm rate is the probability of failing the screening test, given passing on the

criterion task. Miss and false alarm rates are sometimes alternatively referred to as false

negative rate and false positive rate, respectively.

A diagnosis of normal trichromat (Normal or Mild classification) was required for "passing" the anomaloscope test in the Dresent analysis. Passing the anomaloscope was

highly related to performance on the FPS and Aircraft Lights tasks; validities (Cohen's

Kappa) of 0.90 or above were obtained. Several color vision plate tests had comparable high

validities for predicting color discrimination/identification in the FPS and Aircraft Lights

tasks. Plate tests with relatively high validity were those known to have high validity for

screening normal trichromats. The validities of the anomaloscope test were lower for

prediction of performance on the Radar-L task and the ASL task, primarily due to more

simple and extreme anomalous trichromats passing the two ATCS color tasks. The highest

validities were obtained in those cases with the Farnsworth D-15 and Lantern tests. Both

tests are known to pass some individuals diagnosed as simple anomalous by the

anomaloscope (Steen, et al., 1974). In Table 3 (Appendix A3). the data for Radar-S task show

that with small targets, only one subject among the simple and anomalous trichromats

passed. Although many color deficients can discriminate colors in radar displays when

targets subtend 0.5 deg, almost no individual with color vision deficiency can do so when

targets subtend 0.1 deg. The highest validity for prediction of ability to identify color of

small radar targets was again found among those screening tests that are recommended by

the Committee on Vision (1981) for selecting normal trichromats.

The very high predictive validities for the FPS and Aircraft Lights test indicate the

requirement for a high level of color vision ability in normal task performance. Almost all

FAA-accepted color vision tests for the Class I standard have low miss rates, but false alarm

7
rates vary widely. The Farnsworth Lantern has the highest miss rate, and is known to pass

some anomalous trichromats (Steen. et al., 1974). It is recommended that one of the plate

tests with high validity be used for color vision screening of ATCS personnel instead of the

Farnsworth Lantern. The Titmus Tester, Titmus II Tester, and OPTEC 2000 failed a very

high percentage of individuals that could accurately identify red and black in flight strips.

including many normal trichromats. Reliance on those tests will lead to rejection of many

individuals that can perform ATCS color tasks: many rejected will be normal trichromats.

The Three-Test Battery generally had validity that was only slightly lower than the best

plate tests. It should be noted that the validity of the battery, however, was usually less than

the validity for the Dvorine test alone, when the latter is used with the failure criterion of 5

or more errors. Administration of the Farnsworth D-15 and the FCPT does not appear to

add to the value of the battery as a screening tool.

An anomaloscope diagnosis of normal trichromat or a passing score on any one of

several FAA-accepted color vision plate tests that are designed to select normal trichromats

were the best predictors of error-free performance on simulated ATCS color tasks that

involved either actual ATCS task materials, or accurate simulations of the color

characteristics of the actual materials. The validities of those screening tests in the vicinity

of 0.90 or above for prediction of performance on the Flight Strips and Aircraft Lights

tasks, and overall performance are very high. Those validity levels are comparable to the

validity of the same tests in differentiating between normal trichromats and color vision

deficients. The high validities of the better plate tests not only confirm the importance of

normal trichromatic color vision for performance of those ATCS tasks, but also suggest that

there would be little to gain even If it were possible to use simulations of ATCS tasks as

screening tests. Simulations would be more complex to administer and more prone to error

if administered outside a laboratory situation, and it is unlikely that their reliability would

be higher than the validity of the plate tests. The gain in face validity with use of

simulations for screening tests would not be likely to increase predictive validity, and but

would lengthen the color vision testing process, and because of added complexity, make the

screening testing process more susceptible to error.

CONCLUSIONS

Normal color vision is required for performance of certain tasks by ATCS personnel. The

present data show that error in simulated ATCS color tasks was rare among normal

trichromats in normal operating conditions. Only one normal trichromat made an error on

one of the tasks in normal conditions. Many individuals with color vision deficiency made

errors on the ATCS color tasks when normal conditions were simulated. Color vision

deficients were also more adversely affected than normal trichromats by marrinal

illumination conditions In the Flight Strips task and with small targets in the radar task.

Therefore, under adverse conditions, including unexpected situations such as lamp failure,

etc., the probability of error in color identification or discrimination will still be much

lower for normal trichromats than for individuals with color vision deficiency.

The occurrence of some errors in normal trichromats observed in the present study under

adverse observation conditions in the flight strips and radar tasks is also of concern.

Extremely low illumination levels for flight strips should also be avoided and dependence

on nonredundant color coding for identification of small targets on the order of 0.1 deg in

size on radar displays should be avoided. Measures to prevent such marginal conditions

should be considered. Three types of color weather radar displays examined by the author

all have a "zoom' function that can be used to enlarge target size. It should be noted that the

FAA currently requires "Flight Watch" positions (controllers who brief aircraft in flight) at

flight service stations to use a Remote Radar Weather Display System (RRWDS); other types

of briefing positions often do not have that equipment. The RRWDS system has level blink

and level delete special functions, in addition to the zoom function, that can provide

redundant cues in parallel with the color code for weather level. The present findings

8
support the desirability of having and using such special functions in all color weather

radar display systems.

Several color vision screening tests had very high validities for predicting performance

on ATCS color tasks, particularly in the Flight Strips and Aircraft Lights tasks (0.90 and

above). When a passing score was contingent upon passing all four ATCS color tasks, the

predictive validities were even higher, 0.96 for one test. That finding is important, since

ATCS personnel do frequently move from one type of facility to another, due to the

requirements of the ATC system and the needs of individual ATCSs. including the desire for

promotion, etc. Miss rates and false alarm rates for the screening tests with highest validity

were frequently in the vicinity of 5% or less in the overall performance index. While most

of the tests accepted for aeromedical screening have reasonably low miss rates, some had

very high false alarm rates that would cause many individuals, very capable of performing

ATCS color tasks, to fail color vision screening. The latter tests should not be used for ATCS

screening.

These results suggest that use of the Three-test Battery should be discontinued in favor of

one of the more valid plate tests. When the Three-test Battery was applied to prediction of

simulated ATCS color task performance using the criterion of passing two out of three tests,

the validity of the battery was acceptable, but was actually lower than the validities of the

Dvorine test and of several other individual pseudoisochromatic plate tests. Use of the D-15

and FCPT in addition to the Dvorine does not appear to benefit the ATCS color vision

screening process and actually decreases predictive validity. In addition, it is recommended

that the FCPT should not be used for color vision screening because it is not a "pure" color

vision test. For example, because the test is timed and some instructions and questions must

be read during the timed periods, reading speed and comprehension would affect

performance.

Color vision deficients with red-green deficiencies comprise more than 99.9% of all

inherited color vision deficiencies, and the findings of this study apply only to the screening

of those individuals, since blue-yellow (tritan) deficients were not a part of this study. The

question should be raised whether ATCS color vision screening should include testing for

tritan deficiencies. It is felt that because critical ATCS color tasks of the present ATCS

environment involve the colors red, yellow, green, and white, that impact of tritan

deficiencies would be negligible. However, as increasing use of color-CRT workstations is

planned for future ATCS air traffic control and weather information systems, that may not

remain the case. Additional studies are planned to evaluate color displays being developed

for future ATCS use in that regard.

9
REFERENCES

Adams AJ, Tague MK. Performance of Air Traffic Control Tasks by Protanopic Color

Defectives. Am. J. Opt. Physiol. Opt. 1985: 62:744-50.

Box GEP. Some theorems on quadratic forms applied in the study of analysis of variance

problems. I. Effect of inequality of variance in the one-way classification. Ann.

Math. Stat. 1954; 25:290-302.

Cohen J. A coefficient of agreement for nominal scales. Educ. Psy. Meas. 1960; 20:37-46.

Convey JJ. Passing scores for the FAA ATCS color vision test: Report No. FAA-AM-85-7.

Washington, DC: Federal Aviation Administration, Office of Aviation Medicine.

1985.

Illumination Engineering Society. Illumination Engineering Handbook (5th Ed.). New

York: Illumination Engineering Society of New York, 1972.

International Civil Aviation Organization. Airworthiness technical manual. Document

9051-AN/896, Amendment 10. 1000 Sherbrooke Street West, Suite 400, Montreal.

Quebec. Canada. November 14, 1988.

Kuyk TK. Veres III JG, Lahey MA, Clark DJ. The ability of protan color defectives to

perform color-dependent air traffic control tasks. Amer. J. Optom. Physiol. Optics.

198u; 63:682-6.

Kuyk TK. Veres III JG. Lahey MA. and Clark DJ. Ability of deutan color defectives to

perform simulated air traffic control tasks. Amer. J. Optom. Physiol. Optics. 1987;

64:2-10.

Lahey MA. Veres III JG, Kuyk TK, Clark DJ, Smith EN. Job Analysis and Determination of

Color Vision Requirements for Air Traffic Control Specialists. Report submitted

under Contract OPM-50-83 with the U.S. Office of Personnel Management. 1984 (a)

Lahey MA, Kuyk TK. Veres III JG, Clark DJ. The Impact of Color Weather Radar Equipment

on the Job of Air Traffic Control Specialists - Flight Service Station Option. Report

submitted under Contract OPM-50-83 with the U.S. Office of Personnel

Management. 1984 (b)

National Research Council-National Academy of Sciences, Committee on Vision.

Procedures for testing color vision: Report of working group 41. Washington, DC:

National Academy Press, 198i.

Pickrel EW, Convey JJ. Color perception and ATC job performance: Report FAA-AM-83-1 1.

Washington. DC: Federal Aviation Administration, Office of Aviation Medicine,

1983.

Pokorny J. Smith VC, Verriest G, Pinckers AJLG. Congenital and acquired color vision

defects. New York: Grune and Stratton. 1979.

Steen JA. Collins WE. Lewis MF. Utility of several clinical tests of color defective vision in

predicting daytime and nighttime performance with the aviation signal light gun.

Aerospace Med. 1974: 45:467-72.

10
Table I

Color Vision Tests Accepted by the FAA for Airmen Certification

ACCEPTED TESTS FULL TEST NAME ATCS FAILURE CRITERIA

(Cliss I Certification)

Pseudoisochromatic Plate Tests

1. AOC (18-Plate) American Optical Company Pseudoisochromatic 4 or more errors, plates 1-is

Plates - 1940 Edition.

2. AOC (IS-Plate) American Optical Company Pseudoisochromatic 5 or more errors, plates 1-15

Plates - 1965 Edition

3. Richmond Richmond Pseudo-lsochromatic [sic] Plates for 5 or more errors, plates 1-15

Testing Color Perception

4. AOC-HRR American Optical - Hardy, Rand, Rittler any error on plates 1-6

Pseudoisochromatic Plates - Second Edition

5. Dvorine (2nd Ed.) Dvorine Pseudo-Isochromatic [sic] Plates - 3 or more errors, plates 1-15

Second Edition

Ishihara's Tests for Color-Blindness

6. Ishihara (14-Plate) Concise Edition 2 or more errors, plates 1-11

7. Ishihara (16-Plate) 16 Plates Edition 2 or more errors, plates 1-4

8. Ishihiare (24-Plate) 24 Plates Edition 3 or more errors, plates 1-15

9. Ishiar (38-Plate) 38 Plates Edition 4 or more errors, plates 1-21

Lantern Teats

10. Edridge-Green Lantern Edridge-Green Colour Perception Lantern not studied, rarely used

11. Farnsworth Lantern Farnsworth Lantern avg. of more than 1 error per series

12. SAMCTT School of Aviation Medicine Color not mstid, no longe used by USAF

Threshold Tester

Multifunction Vision Testers

13. Keystone Orthoscope/ Keystone Teltbinocular Test Unit, Aeromedical any error

Telebinocular Model

14. OPTEC 2000 OPT EC 2000 Vision Tester, Aeromedical Model any error

15. Titmus Titmus Vision Tester any error

16. Titmus U Titmus U Vision Tester any error

Al
Table 2

Number of Subjects Passing or Failing Four Simulated ATCS Color

Tasks as a Function of Color Vision Deficiency

COLOR VISION CLASSIFICATION

Normal Trichromats Anomalous Trichromats Dichromats

TASK Normal Mild Simple Extreme

Prot Deut Prot Deut Prot Deut

Flight Progress Strips Pass 31 6 1 2 0 1 0 1

(59 lux Illumination) Fail 0 0 4 11 5 16 11 19

Color Weather Radar Pass 30 6 0 9 0 5 0 3

(0.5 Deg Targets) Fail 1 0 5 4 5 12 11 17

Aircraft Lights Pass 31 6 0 2 1 0 0 1

Fail 0 0 5 11 4 17 11 19

ASL Indicator Pass 30* 6 3 9 0 6 1 3

Fail 0 0 2 4 5 11 10 17

ALL TESTS (Fail with Pass 30 6 0 1 0 0 0 0

any error, any test) Fail 1 0 5 12 5 17 11 20

* ASL data were lost for one Normal due to technical error.

A2
Table 3

Number of Subjncts Passing or Failing Simulated ATCS Color Tasks as a

Function of Color Vision Deficiency and Adverse Viewing Conditions

COLOR VISION CLASSIFICATION

Normal Trichromats Anomalous Trichromats Dichromats

TASK Normal Mild Simple Extreme

Prot Deut Prot Deut Prot Deut

Flight Progress Strips

FPS-N (59 lux Illum.; Pass 31 6 2 2 0 5 0 1

Fail 0 0 3 11 5 12 11 19

FPS-L (14 lux Illum.) Pass 29 5 1 0 0 2 0 1

Fail 2 1 4 13 5 15 11 19

Color Weather Radar

Radar-L Pass 30 6 0 9 0 5 0 3

(0.5 deg Targets) Fail 1 0 5 4 5 12 11 17

Radar-S Pass 24 3 0 1 0 0 0 0

(0.1 deg Targets) Fail 7 3 5 12 5 17 11 20

A3
Table 4

Errors on Simulated ATCS Color Tasks as a

Function of Color Vision Deficiency

STANDARD 95% CONF.

TEST DIAGNOSIS MEAN DEVIATION INTERVAL

Flight Progress Strips Normal 0.00 0.00 0.00 TO 0.00

(59 lux illum.) Mild 0.00 0.00 0.00 TO 0.00

Simple 5.22 5.54 2.47 TO 7.98

Extreme 18.05 19.54 9.38 TO 26.71

Dichromat 27.42 20.09 20.05 TO 34.78

Color Weather Radar Normal 0.03 0.18 -0.03 to 0.10

(0.5 deg Targets) Mild 0.00 0.00 0.00 to 0.00

Simple 0.89 1.13 0.33 to 1.45

Extreme 2.18 1.94 1.32 to 3.04

Dichromat 3.06 1.90 2.37 to 3.76

Aircraft Lights Normal 0.00 0.00 0.00 to 0.00

Mild 0.00 0.00 0.00 to 0.00

Simple 3.06 2.84 1.64 to 4.47

Extreme 5.73 3.28 4.27 to 7.18

Dichromat 7.90 3.94 6.46 to 9.35

Aviation Signal Light Normal 0.00 0.00 0.00 to 0.00

Mild 0.00 0.00 0.00 to 0.00

Simple 0.39 0.61 0.09 to 0.69

Extreme 1.14 0.83 0.77 to 1.51

Dichromat 1.55 0.96 1.20 to 1.90

A4
Table 5

Validity of Color Vision Selection Tests for Prediction of Overall

Performance (Fail on Any Task Under Normal Conditions)

ERROR RATE (%)

False Validity

TEST Miss Alarm (Kappa)

Anomaloscope (Pass Normal or Mild) 1.4 2.7 .96

FAA-Accepted Tests (Cliss I)

AOC (15-Plate) 1.4 10.8 .90

Richmond 1.4 16.2 .85

AOC (18-Plate) 4.2 8.1 .88

AOC-HRR 1.4 10.8 .90

Ishihara (14-Plate) 1.4 2.7 .96

Ishihara (16-Plate) 1.4 13.5 .87

Ishihara (24-Plate) 1.4 5.4 .94

Ishihara (38-Plate) 1.4 5.4 .94

Dvorine (Fail 3 errors) 1.4 8.1 .92

Titmus Tester 0.0 73.0 .33

Titmus II Tester 0.0 54.1 .53

OPTEC 2000 1.4 43.2 .61

Keystone 1.4 10.8 .90

Farnsworth Lantern 11.3 2.7 .82

Three-test Battery 5.6 2.7 .90

Dvorine (Fail 5 errors) 1.4 2.7 .96

Farnsworth Panel D-3.5 32.4 0.0 .59

Funct. Color Percept. Test 4.2 73.0 .27

A5
Table 6

Validity of Aeromedical Color Vision Screening Tests for Prediction

of Performance on the FPS Test (59 lux Illumination)

ERROR RATE %)

False Validity

TEST Miss Alarm (Kappa)

Anomaloscope (Pass Normal or Mild) 0.0 11.9 .90

FAA-Accepted Tests (Class I)

AOC (15-Plate) 0.0 19.0 .84

Richmond 0.0 23.8 .80

AOC (18-Plate) 3.0 16.7 .82

AOC-HRR 0.0 19.0 .84

Ishihara (14-Plate) 0.0 11.9 .90

Ishihara (16-Plate) 0.0 21.4 .82

Ishihara (24-Plate) 0.0 14.3 .88

Ishihara (38-Plate) 0.0 14.3 .88

Dvorine (Fail 3 errors) 0.0 16.7 .86

Titmus Tester 0.0 76.2 .28

Titmus II Tester 0.0 59.5 .45

OPTEC 2000 0.0 47.6 .57

Keystone 0.0 19.0 .84

Farnsworth Lantern 10.6 11.9 .77

Three-test Battery 4.5 11.9 .84

Dvorine (Fail 5 errors) 0.0 11.9 .90

Farnsworth Panel D-15 27.3 0.0 .67

Funct. Color Percept. Test 4.5 76.2 .22

A6
Table 7

Validity of Color Vision Selection Tests for Prediction of

Performance on the Flight Progress Strips Subtest Given

Under Both Normal (FPS-N) and Low (FPS-L) Illumination

NORMAL ILLUM. (59 lux) LOW ILLUM. (14 Lux)

Error Rate %) Error Rate (%)

False Validity False Validity

TEST Miss Alarm (Kappa) Miss Alarm (Kappa)

Anomaloscope (Pass Normal 0.0 21.3 .81 4.3 10.5 .86

or Mild)

FAA-Accepted Tests (Class I)

AOC (15-Plate) 0.0 27.7 .75 2.9 15.8 .84

Richmond 0.0 31.9 .71 1.4 18.4 .84

AOC (18-Plate) 3.3 25.5 .73 5.7 13.2 .82

AOC-HRR 0.0 27.7 .75 2.9 15.8 .84

Ishihara (14-Plate) 0.0 21.3 .81 4.3 10.5 .86

Ishihara (16-Plate) 0.0 29.8 .73 2.9 18.4 .81

Ishihara (24-Plate) 0.0 23.4 .79 4.3 13.2 .84

Ishihara (38-Plate) 0.0 23.4 .79 4.3 13.2 .84

Dvorine (Fail 3 errors) 0.0 25.5 .77 4.3 15.8 .81

Titmus Tester 0.0 78.7 .23 0.0 73.7 .32

Titmus II Tester 0.0 63.8 .39 0.0 55.3 .51

OPTEC 2000 0.0 53.2 .50 0.0 42.1 .64

Keystone 0.0 27.7 .75 2.9 15.8 .83

Farnsworth Lantern 9.8 19.1 .72 12.9 7.9 .76

Three-test Battery 3.3 19.1 .79 7.1 7.9 .84

Dvorine (Fail 5 errors) 0.0 21.3 .81 4.3 10.5 .86

Farnsworth Panel D-15 24.6 4.3 .69 31.4 0.0 .61

Funct. Color Percept. Teit 3.3 76.6 .22 4.3 73.7 .26

A7
Table 8

Validity of Color Vision Selection Tests for Prediction of

Performance on Tests Radar-L and Radar-S

LARGE TARGETS SMALL TARGETS

Error Rate %) Error Rate %)

False Validity False Validity

TEST Miss Alarm (Kappa) Miss Alarm (Kappa)

Anomaloscope (Pass Normal 1.8 32.1 .66 12.5 3.6 .76

or Mild)

FAA-Accepted Tests (Class I)

AOC (15-Plate) 1.8 37.7 .61 11.3 10.7 .73

Richmond 1.8 41.5 .57 8.8 10.7 .77

AOC (18-Plate) 1.8 32.1 .70 13.8 7.1 .72

AOC-HRR 1.8 37.7 .61 10.0 7.1 .77

Ishihara (14-Plate) 1.8 32.1 .66 12.5 3.6 .76

Ishihara (16-Plate) 1.8 39.6 .59 11.3 14.3 .70

Ishihara (24-Plate) 1.8 34.0 .65 12.5 7.1 .74

Ishihara (38-Plate) 1.8 34.0 .65 12.5 7.1 .74

Dvorine (Fail 3+ errors) 1.8 35.8 .65 11.3 7.1 .75

Titmus Tester 0.0 81.1 .19 2.5 71.4 .33

Titmus II Tester 0.0 67.9 .32 6.3 57.1 .42

OPTEC 2000 1.8 60.4 .38 8.8 46.4 .48

Keystone 1.8 37.7 .61 10.0 7.1 .77

Farnsworth Lantern 5.5 22.6 .72 21.3 3.6 .63

Three-test Battery 1.8 26.4 .72 16.3 3.6 .70

Dvorine (Fail 5+ errors) 1.8 32.1 .66 12.5 3.6 .76

Farnsworth Panel D-15 16.4 3.8 .80 40.0 0.0 .44

Funct. Color Percept. Test 0.0 75.5 .25 7.5 75.0 .21

A8
Table 9

Validity of Color Vision Selection Tests for Prediction of

Performance on the Aircraft Lights Test

ERROR RATE %)

False Validity

TEST Miss Alarm (Kappa)

Anomaloscope (Pass Normal or Mild) 0.0 9.8 .92

FAA-Accepted Tests (Cla.;s I)

AOC (15-Plate) 0.0 17.1 .86

Richmond 0.0 22.0 .82

AOC (18-Plate) 3.0 14.6 .84

AOC-HRR 0.0 17.1 .86

Ishihara (14-Plate) 0.0 9.8 .92

Ishihara (16-Plate) 0.0 19.5 .84

Ishihara (24-Plate) 0.0 12.2 .90

Ishihara (38-Plate) 0.0 12.2 .90

Dvorine (Fail 3+ errors) 0.0 14.6 .88

Titmus Tester 0.0 75.6 .29

Titmus II Tester 0.0 58.5 .47

OPTEC 2000 0.0 46.3 .59

Keystone 0.0 17.1 .86

Farnsworth Lantern 9.0 7.3 .83

Three-test Battery 4.5 9.8 .86

Dvorine (Fail 5+ errors) 0.0 9.8 .92

Farnsworth Panel D-15 28.4 0.0 .66

Funct. Color Percept. Test 4.5 75.6 .23

A9
Table 10

Validity of Color Vision Selection Tects for Prediction of

Performance on the Aviation Signal Light Indicator Test

ERROR RATE (%

False Validity

TEST Miss Alarm (KaDpa)

Anomaloscope (Pass Normal or Mild) 0.0 37.9 .60

FAA-Accepted Tests (Class I)

AOC (15-Plate) 0.0 43.1 .55

Richmond 0.0 46.6 .51

AOC (18-Plate) 2.0 39.7 .56

AOC-HRR 0.0 43.1 .55

Ishihara (14-Plate) 0.0 37.9 .60

Ishihara (16-Plate 0.0 44.8 .53

Ishihara (24-Plate) 0.0 39.7 .58

Ishihara (38-Plate) 0.0 39.7 .58

Dvorine (Fail 3+ errors) 0.0 39.7 .58

Titmus Tester 0.0 82.8 .16

Titmus II Tester 0.0 70.7 .28

OPTEC 2000 0.0 62.1 .36

Keystone 0.0 43.1 .55

Farnsworth Lantern 2.0 27.6 .69

Three-test Battery 0.0 32.8 .65

Dvorine (Fail 5+ errors) 0.0 37.9 .60

Farnsworth Panel D-15 14.3 10.3 .75

Funct. Color Percept. Test 0.0 77.6 .21

A10
Figure 1

MEAN Flight Progress Strips Errors As A

ERRORS Function of Color Vision Deficiency

20-

Protan 14 Lux Mlum

15- Protan 59 Lux Ilium

Deutan 14 Lux Illum

10- dI

Deutan 59 Lux ilum

5 -........

0-

Simple Extreme Dichromat

DEGREE

B1
Figure 2

MEAN Radar Errors As A Function Of Type Of

ERRORS Color Vision Deficiency, and Target Size

8-

7-

6- rtn01'Tre

5-

3-aletn01*Tre

2-l Deutank O.5* Target

1-

0

0-

Simple Extreme Dichromat

DEGREE

*U.S. MERWThENT PRINTING OF'FICE: 1990-761-020/20292 Region 4.

B2