: FIGURE 5
PREVALENCE OF PATH. CODE 161/1000 AIRMEN BY AGE

RATE PER .
1,000
nw,

Under Age 40

30

20 F]

"10

oe —= n n ;
1967 . 1972 : 1977 - 1982 1987
Path. Code 161 = Contact Lenses YEAR

AG

40,5. Government Print ing Off tee:1990-761-020/20324



To guide future medical certification decisions, FAA policy changes, and education safety
programs to aviation personnel on contact lenses, current information on the use of such
devices by pilots ts essential. This report provides the results of a descriptive, retrospective

_ epidemiologic study of active airmen, by 5-year intervals for the study period 1967-87 to

. calculated by adding the following restriction categories: _

identify the prevalence of both defective distant vision and contact lens use in the civil
airman population. © it

METHODS
The protocol ‘for this study included the determination of three basic categories of data:

() Frequency of airmen with defective distance vision was extracted from the
“Frequency ‘of Restrictions Among Active Airmen by Class and Sex” Table in the
Aeromedical Certification Statistical Handbook (AC 8500-1) (7}, which ts published
ahnually by ‘the Civil Aeromedical Institute's (CAMI) ‘Aeromedical Certification Division.
Totals for specified years (1967 -1976), were calculated by adding the following restriction
categories: « me ‘ Jo oo = an
' a), Must wear glasses for distance vistort while flying: :

b} Must wear glasses for near and distance vision while flying:
c) ‘May wear contact lenses while flying; and wot
‘d} May wear contact lenses while flying: glasses must be available.

juency of airmen with defective distant vision for the specified years (1977-1987) was

a) Must have corrective lenses; .

b) Must have glasses for near and distance vision; ' '
©} Must wear lenses for distance vision and possess glasses for near vision: and
d), Must wear corrective lenses: extra pair must be available. .

(2) Airmen who use contact lenses (pathology code 161) to correct their distance vision
was provided on computer. printouts supplied by the Aetomedical Certification Division's
Statistics. and Records Branch. Staff members’ of the, Aeromedical Research Division's
Vision’ Research Section, extracted totals of airmen issued certificates with the FAA-specific
pathology code 16: from these hard copy printouts. (Note: Prior to Amendment 67-10 to the
FAR, airmen who wore contact lenses were assigned a pathology code {i.e., 161) to their
medical certificate. This code elicited a waiver for certification by the FAA's Aeromedical
Certification Division. Civil Aeromedical Institute in Oklahoma City, Oklahoma. However,
despite the change in Part 67 of the FAR, this same pathology code is still assigned to the
contact lens wearing medical certificate applicant, although it ts no longer considered a
pathology and will not’ elicit a denial for.a certificate when contact lenses are needed to
correct for distant vision (8). Unfortunately, because the submittal of FAA Form 8500-7 by
the examining physictan performing the physical is no longer required, important variables
such’ as lens materials (polymethyimethacrylate, gas permeable, hydrophilic), designs, care
systems, duration of wearing experience. past or present occurrences of contact lens-related
problems, ‘etc., are not normally avatlable. .

(3) Prevalence rates per/1000 airmen by both class and age in the total airman
population were calculated using the population frequencies from the preceding year as the
denominator. These frequencies, which were also extracted from the annual issues of the
Aeromedical Certification Statistical Handbook, AC 8500-1, . were considered most
represcntative of the average population of the year of interest. (Note: The total frequencies
of airmen in 1967 with pathology code 161 by class of medical certificate and by age were



FIGURE 1

TOTAL CIVIL AIRMAN POPULATION
PERCENT WITH DEFECTIVE DISTANCE VISION

40
36.50
34.68 33.39
30r
20F
_10F
0 1967 1972 1977 1982 1987

YEAR



the percentage of contact lens wearers in that population ts considerably Jess than the
estimated 8.8% in the United States population. ©

‘The reduced percentage of corrective lens use in ‘the ‘active airman populatio: (48%)
compared to the U.S. population (54%) may be due to pre-screening of pilot’ applicants.
However, the larger difference in use of contact lenses in the civil airman population
compared to the U.S. population may be explained by a number of factors, including:

) A blag by armen aa result of pas problems in obtaining wares to fy with contac

a Aging (>50 years of age: 9.50% in 1966; 16.98% in 1976; and 21. 67% in 1986) of the
: airman population (11) (Note: It has been estimated that 80% of the contact lens wearers are
between the ages of 18 anid 44 (12); ‘

3) The higher frequency of ‘males in the airman population (15.53:1 ratio of
males:females in 1986 (11) (Note: A Food and Drug Administration survey of Us. contact
ens wearers estimated that females wear 68% of all contact lenses (12).); ‘

” ‘The restriction of contact lenses to correct distant vision ofly; and 1
‘sg The incompatibility of contact lenses with certain Might activities. '

In conclusion, although a small percentage of the total airman population, ‘contact lens
wearers are increasing in ‘prevalence. The faster increase in contact lens use observed in
professional pilots (first-class) compared to general aviation ptlota (third-class) is contrary
to standard pathology code prevalence in the civil airman population (13), while the faster
increase in contact lens use observed in the older age pilot category (>40 years) compared to
younger pilots is contrary to the normal pattern of use in the U.S. population. These trends
may indicate that airmien using contact lenses are generally satisfied with their vision’
performance even within the more demanding flight conditions of air transport and

 coritinue to employ them, even with the additional demands on accommodation inherent

from contact lenses to presbyopic airmen. The increased use of contact lenses in the pilot

population mandates ongoing aeromedical certification review, especially with the variety

of plein iat materials, and applications in flight to ensure the continued safe use of such
devices by airmen in the aational airspace system. “


unequal. All frequencies in other years of the study were equal for both variables. For
completeness sake, the unequal frequencies in 1967 are presented.)

7 RESULTS

On reviewing the civil airman with defective distant vision for the study period.in 5-year
intervals (Figure 1), the percentage of airmen with distant vision restrictions increased by
1.4 times during the study period (in 1967, pilots with defective distant vision constituted
25.66% of the total population; tn 1987, that same. group’ was 36.50% of the total,
population). On. ‘comparing prevalence rates of defective’ distant, vision by class of medical
certificate held (Figure: 2), first-class airmen increased by 2.8 times (16. 9/1000 airmen in
1967 to 45.2/1000 airmen in 1987); second-class airmen’ increased ‘by 1.6 times (75.1/1000

‘airmen in 1967 to 116.9/1000 airmen in 1987); and 'third-class dirmen increased by 1.2

times (165.6/1000 airmen in 1967 to 202.9/1000 airmen in 1987) during the study period.

. On examining civil airman with ‘pathology code 161 for the study period in 5-year
intervals (Figure 3), the perceritage of airmen that use contact! lenses increased by 4.0 times
during the study period (in 1967, pilots who wore contact lenses constituted .79% of the total
‘population; in 1987, that same group was 3.13% of the total population). Qn comparing
prevalence rates of pathology code 161 by class of medical certificate held (Figure 4}, first-
class increased by 29.5 times (.2/1000 airmen in 1967 to 5.9/1000 airmen in 1987); second- |
class airmen increased by.7.7 times (1.2/1000 airmen in 1967 to 9.2/1000. airmen in 1987):
and third-c.ass airmen increased by, 2.5 times (6. 5/1000 airmen in 1967 to 16: 2/1000,

\ airmen in 1987) during the study period. ° ‘

On evaluating prevalence of pathology code 161 toy age OPigure 5), airmen over 40 years of

age‘ Increased by 6 4 times (4.0/1000 airmen in 1967 to 25.6/1000 airmen tn 1987), while ©
vairmen under 40 years of age increased by 3.3 times (10.7/1000 airmen in 1967 to 35.7/1000 .

airmen in, 1987} during the study period.
‘ DISCUSSION AND’ conciusions :
Contact lens use by civilian airmen has increased substantially over the study pertod.

While the percentage of the total civil airman.population with defective distant vision
restrictions increased 1.4 times over the 20-year study period, the percentage of airmen with

contact lenses increased 4 times over the same’ period. The prevalence rates for defective

distant vision indicate that first-class airmen increased approximately twice as fast as for
either second- or third-class during the study period. The prevalence rates for contact lens
use indicate that first-class airmen increased usage by approximately 4 times as fast as
second- or third-class airmen during the study period. Furthermore, the prevalence rates for
contact lens use by age indicate airmen over 40 years of age increased usage approximately 2 ‘
times as fast aa atrmen under 40 years of age during the study pertod.

Ris estimated that 54% of the United States’ population, or 132 million people used some
sort of vision corrective lenses tn 1987. About 16% of these (approximately 21.5 million or
about 8.8% of the total U.S. population) wore contact lenses to correct their vision (9). As of

, January 1, 1988, there were 685,552 active airmen of which some 48% (326,757) required

lens correction for some visual deficiency (10), and approximately 37% (252,852) to correct
defective distant vision. Although the prevalence of contact lenses used has increased in the

_ ¢tvil airman population, the majority of airmen who require distance corrections in order

to qualify for an airman medical certificate use eye glasses to satisfy their vision
requirements. 3.13% of the civil airman population wore contact lenses in 1987, indicating



TABLE 1

Distant Visual Acuity Boguirements

For Civilian Pilots
[First-Class 20/20 in tach eye separately
(Airline Transport) without correction or at least
Second-Class 20/200 in each eye separately
(Commercial) corrected to 20/20 or better with
: 7 corrective lenses @asses or
p ___ . _[ contact lenses)
Third-Clase . ,| At least 20, without correction;
. | or if vision is poorer than 20/50,

(Private)

must correct to 20/30 or better

with corrective lenses (glasses or =

contact _lenses) -



Mind a0 av
DoTmANeie,

Office'of Aviation Medicine”
Washington, D.C. 20591

AD-A227 450

"The Use of Contact
Lenses in the Civil —
Airman Population

Van B. Nakagawara, OD.

Civil Aeromedical Instiouse

"September 1990

‘ Final Report ;

This document is available to the public through
the National Technical Information Service,
Springfield, Virginia 22161...”

awe

U.S. Department ,

of Transportation |
Federal Aviation
Administration


FIGURE 3

TOTAL CIVIL AIRMAN POPULATION |
Pencent WITH PATHOLOGY CODE 161

4
. oF
‘ot
i+
0 1967 1972 1977, 1982 _ 1987
YEAR - ‘

_ Path Code 161 = Contact Lenses



FIGURE 2

PREVALENCE OF D.D.V./1000 AIRMEN BY CLASS

RATE PER
1,000)

240 Fr

0 n n n : v4
1967, 1972 1977) 1982 1987
YEAR
D.D.V = DEFECTIVE DISTANCE VISION



be

10.

uh

12,

13,

REFERENCES

Code of Federal Regulations: Title 14, Part 67. 1988.

Guide for aviation medical examiners. Federal Aviation Administration, Office of
Aviation Medicine. 1981.

Dille UR, Booze CF Jr. The 1975 accident experience of civilian + pilots with static
physical defects. 1977. FAA Office of Aviation Medicine Report No. FAA- -AM- 77-20.

Dille JR, Booze CF Jr. ‘The 1976 accident experience of civilian pilots with ‘static
physical defects. 1979. ‘FAA Office of Aviation Medicine Report, No. FAA-AM-79-19,

Ditle JR, Booze CF Jr. The prevalence of visual deficiencies among 1979 general |

aviation accident airmen. 1981. FAA Office of Aviation 1 Medicine Report No. FAA-
AM-81- M4. soos

United States. Consumer Product Safety Commission, Directorate for’ Epidemtology.
' National Injuty Information Clearinghouse. Product-Calendar Year: 1988-Estimates”
Report. Washington, D.C, 1989.

‘Aeromedical certification statistical handbook. Federal Aviation Administration,
Office of Aviation Medicine. 1967-87. AC ‘8600-1.

Aeromedical certification systems. manual Federal Aviation Administration, Office of
Aviation Medicine. 1984.

‘Bennett I. State of the ophthalmic industry. New York City, me Advisory Enterprises,
1988.

“Booze CF Jr. revaisnes of diecese among active cit airtien. 1988.: PAK Office of
Aviation Medicine Report No. FAA-AM-89-2,

Nakagawara VB. The relevance of vision defects in the medical certification of

. ¢tvilian airman. In: Goss,DA, Edmondson LL, eds. Proceedings of the 1988
Northeastern State Untversity Symposium on Theoretical and Clinical Optometry.
March 25, 1988. Tahlequah. OK, 1988; 59-71.

Herman CL. An FDA survey of U.S. contact lens wearers, Contact Lens Spectrum.
2(7):89-92, 1987. .

Booze CF Jr. Prevalence of selected pathology among currently certified active
airman. 1981. FAA Office of Aviation Medicine Report No. FAA-AM-81-9,



THE USE OF CONTACT LENSES.
IN THE CIVIL AIRMAN POPULATION

INTRODUCTION

‘The Federal Aviation Administration (FAA) and its predecessors have been responsible

for the medical certification of all United States and some international civil airmen since

1927, All civilian pilots in the U.S. must maintain 3 current medical certificate of the

: appropriate class to validate any pilot's license they hold. Medical standards are contained

in Part 67 of the Federal Aviation Regulations (FAR) (1). The FAA publishes a “Guide for

Aviation, Medical Examiners,” which provides procedural guidelines for testing pilot
applicants (2).

. ‘The classes of medical certificates for civilian pilots include:
i 1) First Class - Airline Transport Pilot,
" 2) Second Class - Commercial Pilot, Flight engineer, and Flight Navigator. and
‘ 3) Third Class + Private Pilot (2). . . .

Prior to 1976, ‘civilian airmen were not allowed to use contact lenses while flying unless a
watver had been issued by the FAA. If an applicant did not meet the medical standards for
the certificate class applied for, a Statement of Demonstrated Ability (SODA) could be issued
by the FAA (2). For example, if an applicant had no prior SODA for a failed vision standard,
further consideration for a waiver by the FAA could be initiated by submitting a report of
an eye evaluation (FAA Form 8500-7, “Report of Eye Evaluation”) (2). After Amendment 67-
10 to the FAR, effective on December 21, 1976, permitted the routine use of contact lenses to
satisfy the distant visual acuity requirements of Part 67, the SODA process was eliminated
in most instances. (Note: Distant visual acuity requirements for the different classes of

_ medical certificates are found.in Table 1.) (2).

Several epidemiologic studies have been performed by the FAA on the association of
contact lenses to aviation accident risk. Dille and Booze in a 1975 study found the use of
contact lenses had only marginal significance (1.7., significant at p< 10) for increased
accident rates (3). In a follow-up study of accident rates of civil airmen in 1976, use of
contact lenses. was associated with significantly (1.¢., significant at p < .01) more accidents.
(4). However,.in a 1979 study of general aviation accident airmen, contact lens wearers had
less than average accident experience {i.e., not significant at p < .10) in contrast to previous
studies (5). Therefore, evidence on the association of contact lens wear to aviation accident
risk has been inconclusive.

rN a

Z y Despite lack of conclusive aceident risk, contact lens use merits constant vigilance by the

_ FAA. Civil aviators may experience problems with contact lenses while fying. such as
{_* teritation while using full-face ‘self-contained breathing apparatus or other protective
) devices; dislodged lenses while performing acrobatic ‘maneuvers; visual performance
/ decrement in aviation physiologic environments (e.g.. hypoxia, hypobaria, low relative

humidity); additional demands on accommodation inherent from contact lenses to

presbyopic airmen: and compromised flight operations when using certain lens designs.
. Furthermore, according to a study by the Consumer Product Safety Commission, it was
j estimated that more than 30,000 injuries, including reports of contusions, foreign bodies.
lacerations, ete.. related to contact lens wear occurred in 1988 (6). implying inherent
hazards of such devices.

|
i
|
i
\



~ END
- FILMED



ACKNOWLEDGEMENTS

The author gratefully acknowledges the assistance provided by
Ms, Kathryn J. Wood, Opt. T.R., of the Vision Research Section
who ‘assisted in the review of the computerized databases and
provided graphics support; and the late Charles F. Booze, Jr., Ph.D.,
and Ms. Leslie Downey, staff members of the Statistics and Records
Branch, Aeromedical Certification Division, who provided
consultation and technical support throughout the project. |

"Accession For

ieee

NTIS GRA&I

DTIC TAB :

Unannounced im]
Justification _—___-__-
Distribution/
Availability Codes
w~Vievcil and/or

Epeotal

iil/iv


Technical Report Documentation Page

T) Report No. 2 Gove

DOT/FAA/AM-90/10

vament Accession No. T. Recipient's Cotalog No.

T_ Tittle end Subtle

Repent Date
September 1990

Civil AL

The Use of Contact Lenses in the rman G. Performing Organi zation Code my
Population ' . ' : ; ‘
Janets 8. Performing Orgeni zation Report No.

Van B. Nakagawara, 0.D.

F. Performing Organi zetion Nome ond Address

FAA Civil, Aeromedical Institute:
P.O. Box 25082

Oklahoma City, OK 73125"

TO. Werk Unit No. (TRAIS)

TT. Contract or Grant No.

T2. Spondering Agency Nome ond Address
Office of Aviation Medicine ©

“ g00 Independence Avenue, S.W.
Washington, DC 20591

, Federal Aviation Administration ,

TS. Type of Report and Period Covered

Ta. Sponsoring Agency Code

"15. Supplementary Notes .
| Thia work,

Adverse Environments. Di, Nakagawara presented

ander rash AM-A-89-PHY-144, was initiated after « sequest by the
Vision, to provide a biiefing on the FAA's experience ‘with contact lenses to the Comraittee’s Working Group on Contact Lens Use in

National Research Council, Commitee on

in March 1989. ‘

76. Abstract

| Afedera

x.
\ obta
ifying
contact len

requirements for
informatien ident
vision. and

changes,.
descriptive,

airmen who use cont
period, When stratified
‘the prevalence rates
certificates and ol
increasing use of cont
materials, and applicat

2 paper eo the ‘Working Group at the Univenity of California, Berkeley

L Aviation Regulations permit, the
lenses by, civilian pilots to satisfy the

required td guide future
and education sa
retrospective epidemiologic stu
active airmen by 5-year
1987) using FAA dataoases and publ
act lenses quadrupled during the study

der airmen’ showed ‘the larges

population mandate ongoing rev

routine use of contact
distant visual acuity
ining medical certificates. Specific
the prevalence’ of both defective distant
ses in the civil airman population is
medical certification decisions, policy.
fety programs..to aviation personnel. A
dy was performed of
intervals for a 20-year period (1967-
ications. The percentage of

by ¢
for a

lass of medical certificate and age,
irmen with first-class medical
t increases. The
act lenses and the variety of design,
fons which may be employed by the pilot
dew for. adverse, changes and safety

Medical Certification,

consequences. flr urt:.
17, Koy Words TE. Distribution Statement
. Document is available to the public
P- Vision.- through the National Technical
Contact Lens - Information Service, Springfield,
Epidemiology ‘—

Virginia 22161

19. Security Clovsil, (of this reper!)

Unclassified

Unclassitied

1. (of this page) Tie No, of Peges

15

22, Pree

Form DOT F 1700.7, (8-72

Reproduction of completed pope cuthorized



; FIGURE 4 ;
ALENCE OF PATH. CODE 161/1000 AIRMEN BY CLASS

_ RATE PER.
_ 1,000

4]

i : rm i

o! an
1967 1972 1977 . 1982 1987

Path. Code 161 = Contact Lenses YEAR