1746 ALBERT E. SLOANE AND J. ROSWELL GALLAGHER

3. Loewenstcin, A., and Foster, J.: Malignant melanoma of limbus and spontaneous cyst of pig-mented layer of iris in same sector. Arch. Ophth., 37 :8-17 (Jan.) 1947.

4. Frangois, J.: Kystes des proces ciliares, observes par la gonioscopie apres enclavement de l'iris. Ophthalmologica, 116:313, 1948.

5. Dunnington, J. H.: Personal communication. 6. Greeff, R.: Befund am Corpus ciliare nach Punction der vorderen Kammer. Arch. f. Augenh.

28:178,1894. 7. Wintersteiner, H.: Ueber primare (idiopathische) pigmentierte Cysten der Irishinterflache. Ber.

d. Ophth. Ges (Heidelberg), 33:345-359, 1906. 8. Pagenstecher, H. E.: Multiple Zysten an der Irishinterflache und am Corpus ciliare. Arch. f.

Ophth., 74:290-293, 1910. 9. Meek, R. E.: Sarcoma of the iris (complicated by a cyst). Arch. Ophth., 8:864-870, 1932. 10. Elschnig, H.: Ziliarkorperzyste. Klin. Monatsbl. f. Augenh., 74:476-483, 1925. 11. Villard, H., and Dejean, C.: Les kystes de l'iris. Arch, d'opht., 50 :91-121, 1933. 12. Dunnington, J. H.: Personal communication.

T H E V I S I O N O F A D O L E S C E N T B O Y S

ALBERT E. SLOANE, + M.D. Boston, Massachusetts

AND

J. ROSWELL GALLAGHER,* M.D. Middletown, Connecticut

Both school1 '6 and industry7 '8 have, within the past few years, become increasingly aware of the importance of vision testing and consequently several screening devices8

have been developed. The purpose of these screening devices is to select those persons whose vision requires professional eye care ; the value of such a device is appraised on the basis of its ability to pick out all those who really need this extra examination without needlessly referring many others.

Recently studies of the relative efficiency of several screening devices have been un­dertaken.8"10 One part of the general problem of developing good screening methods is the determination of the ranges of visual data which one finds when an unselected group is examined. A study of such data will assist in determining what should be accepted as the normal limits for any given test and will also

* From the Department of Health, Phillips Academy, Andover, Massachusetts. This study was aided by a grant from The Grant Foundation, Inc.

t Director, Department of Refraction, Massa­chusetts Eye and Ear Infirmary.

| College physician, Wesleyan University.

permit an advance estimate of what the ex­amination of any group is likely to reveal.

I t is to be remembered, however, that a high frequency of any particular finding does not necessarily indicate that it is the optimum condition: naked vision of 20/20 occurs in a much higher percentage of adolescents than does any other figure, but this is not incon­trovertible evidence per se that 20/20 vision is optimal or necessary for all persons.

M E T H O D

This paper presents data obtained at the screening eye examinations of 1,129 differ­ent adolescent males ranging in age from 13 to 19 years. None of these individuals was included in a previous report6 so the data in that report may suitably be compared with the present findings. All the data were ob­tained over a three-year period at the time of the annual health examination of students at a preparatory school. The same technician did all these screening tests, and all were carried out using a modification of the Mas­sachusetts Vision Test.9 The efficiency of this screening device has previously been

V I S I O N O F A D O L E S C E N T BOYS 1747

discussed8'9 and will be the subject of a future report.11 The slight variation in visual acuity which is found at each age in the 13-to 19-year period1'4,1Z makes the division of these data into separate age groups un­necessary. In the Massachusetts Vision Test a cyclopegic is not used.

RESULTS AND COMMENTS

VISUAL ACUITY Visual acuity was determined without

glasses if these were worn. A properly il-

20/ 20 20/ 25 20 / 30 2 0 / 40 20 / 50 20 / 70 20/100 20/200 20/200 plus Eye absent

Total

681 92 54 45 32 36 57 83 48

1

1,129

60.3 8.2 4 .8 4 .0 3.0 3.2 5.0 7.3 4.2 0.09

100.09

luminated American Optical Company chart No. 1,930 at 20 feet from the subject was used. More than two errors in the 20/20, 20/25, and 20/30 lines and more than one error in the 20/40, 20/50, and 20/70 lines was considered a failure of that line.

Table 1 indicates that 72.0 percent of this group had 20/20 binocular vision. This fig­ure is similar (76.5 percent) to that obtained with the same test upon a different group of 797 boys9 and to that reported (80.06 per­cent) on a group of 715 boys;6 and similar to that of Collins and Britten1 who found 69 percent of boys in the 13- through 16-year period to have 20/20 vision or better in both eyes. The lower figure for the last group can be explained on the basis of its referring to 20/20 vision in each eye, while the other reports refer to 20/20 vision when both

of a eyes are used together to read the chart. isual On the basis of referring for a further ex-e 13- amination all those who had less than 20/25 ision vision in one eye, about 30 percent of the ; un- group described in Table 1 would have been Test selected; if the basis were less than 20/25

vision in both eyes, 26 percent would be re­ferred; if only those whose vision was less than 20/30 in one or 20/30 in both eyes were considered, about 25 and 21 percent respec-

thout tively would be referred. It is to be remem-ly il- bered that 350 members of this group (31

724 79 37 38 33 41 43 87 47

0

1,129

64.1 7.0 3.3 3.3 3.0 3.6 3.8 7.7 4.2 0

100.0

811 50 25 37 36 30 44 65 30

1

1,129

72.0 4 .4 2.2 3.3 3.2 2 .6 3.9 5.8 2.6 0.09

100.09

chart percent) already had glasses; only 19 boys : was out of the 1,129 failed the plus-1.50 test so 0/20, we may assume that the majority who were I one wearing glasses were doing so because of lines myopia or astigmatism. With this in mind, a

referral figure of 30 percent does not seem f this excessive. s fig- It is generally believed that the visual ained acuity rating obtained in a school vision-test-jroup ing program tends to be lower than that sub-> per- sequently found by the eye specialist. This milar is probably due to the poorer illumination of id 69 the school charts, the poorer condition of the -year school charts, the fact that the school ex-both aminer is more pressed for time and also

p can tends to give a line-lower rating in case of rig to any doubt than does the specialist. other These factors did not operate in a signifi-both cant degree in the testing described here and,

TABLE 1 VISUAL ACUITY WITHOUT GLASSES

1,129 different male adolescents ranging from 13 to 19 years of age

O.D. O.S. O.U.

Number of Percent of Number of Percent of Number of Percent of Cases Cases Cases Cases Cases Cases

1748 ALBERT E. SLOANE AND J. ROSWELL GALLAGHER

therefore, it is possible that a considerably higher percentage of these students would have failed the 20/30 line had the tests been done in the usual sort of school situation. If this is true, it might be well to consider fail­ure of the 20/40 line the proper level for referral in school screening test rather than the 20/30 line; on this basis about 18 percent would be referred.

HYPERMETROPIA

The presence of hypermetropia was de­termined by instructing the examinee to at­tempt to read the 20/20 line on the Snellen chart through a pair of plus 1.5D. sph. Ability to read this line with either or both eyes was scored as a failure.

In a previous study of 797 boys9 there were 518 who did not wear glasses; 36 of these (6.9 percent) had 20/20 vision in one or both eyes through plus 1.5D. sph. and were therefore rated as failing the test for hyper­metropia.

Another group,6 similarly tested, showed that 10 percent of 466 boys who did not have glasses failed this test. The significance of the data relating to this group is no more than an indication of the number of failures this test may produce when members of this age group and socio-economic level are ex-

TABLE 2 DISTRIBUTION OF HYPERPHORIA MEASUREMENTS

Glasses were worn by the 350 individuals

Prism Diopters

who owned them

Number Tested

without Glasses

Right hyperphoria 5 4 3 2 1

1 0 1 2

22 Left hyperphoria

5 4 3 2 1

Unable to do Orthophoria

Total

2 0 0 3 7 3

738

779

Number Tested with

Glasses

2 1 1 1

IS

1 0 1 3

15 2

308

350

Total Number Tested

3 1 2 3

37

3 0 1 6

22 5

1,046

1,129

amined. There were only about two percent of the 779 who did not have glasses who failed this test. A considerable number of the 350 who already had glasses un­doubtedly had hypermetropia, but these data do not permit an estimate of what that num­ber might be. In a similar series 16 out of 62 boys who were wearing glasses at the time of their first screening examination were known to be wearing them because of hyper-opia, hypermetropic astigmatism, and so forth. On the basis of that small series, one might expect to find that about 25 per­cent of such a group wear glasses because of some type to hypermetropia.

Measurements for heterophoria (distant) were determined at 20 feet. The subject viewed letters and numbers which formed a Maddox cross and a one centimeter light through spectacles in one pair of which a red multiple Maddox rod was mounted horizont­ally for the right eye and in the other pair of which a red multiple Maddox rod was mounted vertically for the right eye.9 The examinee wore his own glasses under these spectacles if he had glasses.

HYPERPHORIA

Table 2 gives the distribution of Maddox-rod measurements. Five boys were unable to give a response which could be interpreted and 19 (1.69 percent) had more than one prism diopter of hyperphoria. These figures are similar to those in two other surveys9'6

utilizing the same test, which reported more than one prism diopter of hyperphoria in 1.5 percent out of 797 boys in one group, and 2.5 percent in the other group of 715 boys.

ESOPHORIA EXOPHORIA (DISTANCE)

Only 1.2 percent of this group were found to have more than six prism diopters of esophoria (distance) with the Maddox-rod test; 1.9 percent had more than four prism diopters of exophoria (table 3) . This total of 3.1 percent having an excess of the stand­ards9 set for esophoria and exophoria (dis­tance) is similar to the finding of 3.1 per­cent and 5.7 percent in two other groups.9'6

VISION OF ADOLESCENT BOYS 1749

In a study13 of 100 candidates for submarine school, two individuals were found to have more than six diopters of esophoria and one had more than four diopters exophoria (dis­tance). A phorometer with Risley prisms and Maddox rods was used and a one-centi­meter light was viewed without glasses at 20 feet.

ESOPHORIA—EXOPHORIA (NEAR)

Heterophoria for near vision was meas­ured by use of a calibrated card held at 16 inches and viewed through 3.0D. prisms mounted base-up for the right eye and base-down for the left eye.9

A total of 22 (two percent of the group) boys failed to meet the standards set for this test; about 0.5 percent of the 1,129 boys in this group were found to have more than six diopters of esophoria (near) and 1.5 per­cent to have more than eight diopters exo­phoria, near (table 4) . Twenty out of 797

TABLE 3 DISTRIBUTION OF ESOPHORIA AND EXOPHORIA

MEASUREMENTS AT DISTANCE Glasses were worn by the 350 individuals

who owned them

Number Number Prism Tested Tested

Diopters without with Glasses Glasses

Total Number Tested

Esophoria 1 2 3 4 5 6 7 8 9

10 or more Exophoria

1 2 3 4 5 6 7 8 9

10 or more Unable to do Orthophoria

157 70 34 12 6 7 6 0 3 0

57 16 8 3 2 2 2 1 3 0 2

388

36 27 12 4 5 4 0 2 3 0

31 11 10 3 3 2 3 1 3 0 3

187

193 97 46 16 11 11 6 2 6 0

88 27 18 6 5 4 5 2 6 0 5

575

TABLE 4 DISTRIBUTION OF ESOPHORIA AND EXOPHORIA

MEASUREMENTS (NEAR) Glasses were worn by the 350 individuals

who owned them

Prism Diopters

Number Tested without Glasses

Number Tested

with Glasses

Total Number Tested

Esophoria 1 2 3 4 5 6 7 8 9

10 11 12 13 13 plus

Exophoria 1 2 3 4 5 6 7 8 9

10 11 12 13 13 plus

Unable to do Orthophoria

70 32 16 7

10 3 2 0 0 1 0 0 0 0

88 39 24

6 12 4

10 5 2 4 1 0 3 0 8

432

42 19 3 8 1 0 2 0 0 0 0 0 1 0

37 15 9 3 7 4 5 5 2 3 0 0 1 0

17 166

112 51 19 15 11 3 4 0 0 1 0 0 1 0

125 54 33

9 19 8

15 10 4 7 1 0 4 0

25 598

Total 779 350 1,129

Total 779 350 1,129

boys in another group (2.5 percent) tested in the same manner9 had more than six di­opters esophoria or more than eight diopters exophoria; in another similar survey6 of 715 boys, 2.7 percent exceeded those degrees of heterophoria. In the study of submarine candidates,13 the subject's gaze was directed at the light bulb of an ophthalmoscope fixed at eye level at 13-inches distance and at­tached to a phorometer.

With these three methods, and a re-test of each, the number exceeding six diopters of esophoria varied from zero to three percent and those exceeding eight diopters exophoria varied from 15 to 34 percent. The variability of heterophoria tests both in amount and kind is well known;14 that these data show as much similarity as they do (except in the

1750 ALBERT E. SLOANE AND J. ROSWELL GALLAGHER

instance of the submarine candidates' exo-phoria at near) is surprising and suggests that the results are reasonably reliable.

The desirability of including tests for heterophoria has been reported9. In that survey, 25 boys out of a group of 518 who did not have glasses failed these tests but passed the tests for visual acuity and hyper­metropia.

S U M M A R Y

1. One obstacle in the development and use of proper visual-screening tests in schools and industry has been the difficulty of determining normal (or, better, optimal) limits for the findings each test produces. This report provides the distribution of vari­ous test results at the vision examination of 1,129 boys ranging in age from 13 to 19 years. The vision examination was part of these adolescents' annual health examination and the screening method used was a modi­fication of the Massachusetts Vision Test.

2. About 72 percent of this group had 20/20 naked binocular vision.

3. If the basis for referral was set at fail­

ure to read the 20/30 line with one eye, the usual acuity test would have selected about 25 percent; if the basis was failure to read 20/30 with both eyes, about 21 percent; if the basis was failure to read the 20/40 line with both eyes, 18 percent would be referred to a specialist.

4. The test for hypermetropia was done with glasses, if the subject had them; 350 members of this group already had glasses. Two percent of those who did not have glasses (779) failed this test.

5. More than one prism diopter of hyper-phoria was found in 1.69 percent; more than six prism diopters of esophoria in 1.2 per­cent ; more than four prism diopters exo-phoria in 3.2 percent. At near there was more than six prism diopters esophoria in 0.5 percent and more than eight prism di­opters exophoria in 1.5 percent.

6. Attention is called to the desirability of including tests for hypermetropia and heterophoria as well as for visual acuity in any screening method.

243 Charles Street (14).

REFERENCES

1. Collins, S. D., and Britten, R. H.: Variation in eyesight at different ages as determined by the Snellen test. Pub. Health Rep., 39:3189-3194 (Dec.), 1924. (Reprint number 979.)

2. Collins, S. D.: The eyesight of the school child as determined by the Snellen test. Pub. Health Rep., 39 :3013-3027 (Nov.), 1924.

3. Kempf, G. A., Jarman, B. L., and Collins, S. D.: A special study of the vision of school children. Pub. Health Rep., 43 :1713-1739 (July), 1928. (Reprint number 1235.)

4. Ciocco, A.: Changes in the types of refractive errors of children. Pub. Health Rep., 53:1571-1578 (Sept. 3, 1936. (Reprint number 1980.)

5. Sloane, A. E.: Massachusetts Vision Test. Arch. Ophth., 24:924-939 (Nov.), 1940. 6. Sloane, A. E., and Gallagher, J. R.: A summary of findings at the eye examination of preparatory

school boys. Am. J. Ophth., 26:1076-1083 (Oct.), 1943. 7. Kuhn, H. S.: Significance of visual defects in war production effort. J.A.M.A., 123:1085-1087

(Dec), 1943. 8. Imus, H. A.: Visual testing techniques. Tr. Am. Acad. Ophth., Mar.-Apr., 1948, pp. 370-385. 9. Sloane, A. E., and Gallagher, J. R.: A practical ophthalmic test which furnishes quantitative

data. Arch. Ophth., 31:217-222 (Mar.), 1944. 10. Foote, F. M.: Progress report: Start of the joint vision testing study. New York, National

Society for the Prevenion of Blindness, (Mar) 1948. 11. Sloane, A. E., and Gallagher, J. R.: Comparison of screening test and ophthalmologist's find­

ings. In preparation. 12. : Changes in vision during adolescence. Am. J. Ophth., 33 :1538, 1950. 13. Sulzman, J. H., Cook, E. B., and Bartlett, N. R.: Comparative study of measures of heterophoria.

Bureau of Med. and Surg. Research Project Number X-493 (Av-263-p) U. S. Submarine Base, New London, Conn., 22: (Feb.), 1946.

14. Bielchowsky, A.: Lectures on Motor Anomalies. Hanover, N.H., Dartmouth College Publications 1940.