Journal of the

OPTICALOf AMERICA

VOLUME 33, NUMBER 6

Symposium on Color-Blindness

Foreword

WHEN the OSA Board of Directors invited~V the Inter-Society Color Council to meet

with the Optical Society in the winter of 1943, itwas suggested that a symposium on color-blind-ness be arranged for the Optical Society by theISCC. Since the Council had already planned todiscuss this subject at its own meeting, it was aneasy matter to expand these plans and arrangefor a more formal and complete presentation ofthe subject.

A number of people were consulted in thedevelopment of this program, among them Armyand Navy representatives. The concensus wasthat two groups of papers would be currentlymost useful, one to lay the background for under-standing the facts of color-blindness, the method-ology necessary in test preparation, a story oftests already developed, and a statement fromthe Armed Services regarding the reason for theirneed of men with normal color vision; the otherto present current test developments in thiscountry. We had hoped to include a history ofwork in color vision, but the time necessary toprepare such a paper was not available either toDr. Hecht or Dr. Judd, who might in other timeshave done this for us.

The emphasis in this program has been uponinformation necessary to the understanding, use,and development of tests and test methods fordiscovering and diagnosing human color visionthat departs from what we have come to consider"normal." In the development of the test de-

scribed by Dr. Hardy in this program, cooperatingCouncil members came more and more to therealization that material which was well knownto the psychologists among them was often newto the physicists and medical men, that informa-tion widely known and used by physicists wasnot well known to psychologists, and that thelanguage and knowledge of the medical man wasoften Greek to both the physicist and psychol-ogist. Methodology of test preparation andpresentation became increasingly important asISCC test work went on, for it was found that aslight difference in method of presenting the testto a subject would sometimes produce unexpectedand disturbing results. To the psychologist thiswas not news; we hope it will not be news to OSAworkers after the papers of this symposium be-come available to them.

The first section of the program was built uponthe idea of covering all the necessary factualmaterial for practical work, relating the papersas far as possible by an exchange among theauthors before publication. This exchange hasbeen carried out, and while it will be evident thatthere are still certain differences in points of viewexpressed by the first three authors, many otherpoints of disagreement were resolved after dis-cussion and exchange of papers. The "pre-audit"of these papers is a contribution made by theCouncil through the cooperation of Dr. Judd,Dr. Dimmick, and Dr. Murray, whose papers

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SOCIETY

JUNE, 1943

DEANE B. JUDD

constitute the first part of the symposium. Thesethree papers appear in this number of the journal.As a part of this first section of the program it wasexpected that Army and Navy representatives,officially appointed to attend this meeting, wouldpresent a picture of just what they require ofcolor vision tests. Although they were not readyto do this by the time of the meeting, they wereable to take the opportunity provided by themeetings to hold many informal discussions. Thisopportunity, we believe, is a contribution quiteas important as the formal presentations on thesubject.

JOURNAL OF TIE OPTICAL SOCIETY OF AMERICA

The second section of the symposium is devotedto a description of tests that are under currentdevelopment, tests to provide information re-garding various aspects of color vision defects.The committee found five such tests that had notpreviously been reported, and Dr. Hecht, Dr.MacAdam, Mr. Jobe, Mr. Farnsworth, and Dr.Hardy were invited to describe the one withwhich each was associated. These reports willappear in later issues of this journal.

DOROTHY NICKERSON

Chairman, Program Committeefor March 1943 Meeting

VOLUME 33, NUMBER 6 JUNE, 1943

Facts of Color-Blindness*

DEANE B. JUDDNational Bureau of Standards, Washington, D. C.

1. EARLY HISTORY

COLOR-BLINDNESS is a subject requiringstatistical treatment; there are types of

color-blindness and a greater or lesser adherenceof groups of observers to these types. These factsare disclosed in a literature which is sufficientlyextensive itself to require statistical treatment.Figure 1 shows the distribution of titles accordingto decade for a fairly complete bibliography oncolor-blindness. To present some semblance ofhistorical perspective, it is convenient to sum-marize the discoveries about color-blindness upto 1855 before attempting a summary of present-day knowledge.

According to this bibliography there appearedin 1684 in the Philosophical Transactions of theRoyal Society an account by D. Tuberville of"Several Remarkable Cases in Physick RelatingChiefly to the Eyes."'" This is perhaps the firstpublished indication that there is such an abnor-mality as color-blindness. Ninety-three yearslater the indication is definite. J. Huddartpublished in the same transactions (1777) an

* P1aper presented at the Symposium on Color-Blindnessat the meeting of the Optical Society of America, NewYork, March 5-6, 1943.

account "Of a Person Which Could Not Distin-guish Colours,"' 8 and Whisson in 1778 published"An Account of a Remarkable Imperfection ofSight. "57

However, not until Dalton's account of hisown case appeared in 1798 in the Memoirs of theLiterary and Philosophical Society of Man-chester2 could it be said that a lucid descriptionof color-blindness had been given. Dalton said ofthe spectrum (p. 31), "I found that persons ingeneral distinguish six kinds of colour in the solarimage, namely, red, orange, yellow, green, blue,and purple. Newton, indeed, divides the purplein indigo and violet; but the difference betweenhim and others is merely nominal. To me it isquite otherwise. I see only two, or at most three,distinctions. These I should call yellow and blue,or yellow, blue and purple. My yellow compre-hends the red, orange, yellow, and green ofothers; and my blue and purple coincide withtheirs." And elsewhere (p. 34), "Woolen yarn,dyed crimson, or dark blue is the same to me."

Dalton's explanation for his abnormal visionwas that his eye media must absorb the red endof the spectrum strongly and so prevent him fromseeing as others did. In commenting on this

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