Color vision is an attribute of the human perceptual array thatperhaps developed in order to aide in survival. The ability todistinguish colors has long been an asset in finding food, avoidingpredators and enjoying the beauty in the environment. As long as manhas had the ability to see the world in color, the questionìhowî has been asked (Color, 2002).
In ancient Greece, Empedocles was close to being correct with afour-color doctrine based on the colors black, white, yellow-greenand red. In the Middle Ages, a man named Alhazen said that vision isa passive experience. During the Renaissance several people proposednew ideas. Leonardo da Vinci favored a three-color theory over thefour colors of Empedocles (Crone, R.A. 1999). He also replaced theyellow-green with plain yellow. During this same period, JohannesKepler posed the question of whether or not we see with the eyes orwith the brain. At the close of the Renaissance, there was ascientific revolution which involved great minds such as Kepler,Galileo, Descartes, and Newton.
Finally, in the early 1800s, a man named Thomas Young developed atheory based on some color matching experiments that stated thatcolor vision is dependent on three cone types in the eye and thewavelengths that they respond to (Padgham & Saunders 1975).Hermann von Helmholtz agreed with this theory and supported itthrough his own work. Basically, the procedure for the color matchingexperiments done by Young and Helmholtz started by findingparticipants with normal color vision. The participants were thenasked to adjust three wavelengths to match the color of a singlewavelength. Since it was possible to match the color exactly withthree wavelengths (Motokawa, 1970), it was concluded that the eyemust have three receptor types. A different wavelength groupingactivates each type. There are cones for short wavelengths such asblues and violets, the medium wavelengths like the greens, and thelong wavelengths like reds and yellows.
In the 1960s, Scientists discovered that there were threedifferent types of cones in the human eye. They had maximumabsorption at 419 nm in short wavelengths, 531 nm in the middlewavelengths, and 558 in the long wavelengths (Goldstein 2002).
Color vision is possible with only two receptor types; however, areduced number of colors can be seen. This is called color deficiency(Neitz Color Vision Lab 2002). With only one active cone type, it isnot possible to see color differences, only varying shades of thesame color. There are three types of color deficient people.Protanopia, which affects about 1.02 percent of people, allows visionof shorter wavelengths such as blue and long wavelengths as yellow.Deuteranopia affects about 1.01 percent of the population and worksalmost the same as protanopia, but has a neutral point of 498 nminstead of 492 nm. Tritanopia is the most rare, affecting about .003percent of the population. They see blue as short wavelengths and redas long wavelengths and have a neutral point of 570 nm (Goldstein,2002).
Even though people with color deficits make up a small number ofthe population, they should be considered in the design of everydaymaterials whose recognition depends on color. Many people have tolearn to deal with this delimma. There are several social andoccupational implications of defective color vision (Color Blindnessor Color Deficiency 2002). Artists must be able to distinguish thecolors they are using or they must adapt. One artist went so far asto use only black and white paints. Electricians must be able todistinguish color so that they can avoid electrocuting themselves.Police officers must be able to give descriptions of people and carsusing the color of paint or clothes. Several other jobs rely heavilyon the ability to discern different colors. The loss of colordiminishes the pleasure of our everyday lives. Even though at timesit seems color is a luxury rather than a necessity (Delman. 2001),perhaps, even for the unskilled laborer, the ability to perceivecolor would improve the quality of life.
The inability to distinguish business signs would make identifyingadvertisements much more difficult. Since business signs often relyon color to distinguish them from other signs, I propose anexperiment designed to test the colors used on signs. I eventuallyhope to find new colors for those signs which will put color deficitpeople on even ground with those who have normal trichromatic visionwithout decreasing the visibility of the signs for anyone. Somesigns, which involve red and blue color schemes or white and yellowcolor schemes are difficult to read.
Over a one-year period, eighty (80) people will be solicited,twenty (20) people with normal color vision and twenty (20) of eachtype of color defiecient person. All must have 20/20 or corrected20/20 vision.
In an attempt to reduce variables such as time of day and lightingconditions, an indoor-lighted range will be constructed. The Buildingwill have dimensions roughly the length of a football field, 110yards, and the width of a normal house, or about fifty (50) feet.Inside the building will be fifteen (15) lanes, similar to those in ashooting gallery which will have markers at 25, 50 and 100 yards.Each lane will be walled off and individually lighted. There willalso be a briefing room and an office. All information will be storedon a computer and 3.5-inch floppy disks as back up. Also, the fivetypes of colr schemes most difficult to distinguish, will be needed.They will be found using another experiment.
The design will be a three by four by five between subjectsdesign. There will be the three distances. There will be the threetypes of dichromats, plus a control of normal trichromats. Finally,there will be the five different business signs. Each person willview all the signs.
At the beginning of the experiment, the groups will be briefed andasked to sign a disclaimer. Groups will be taken five at a time, asthey are found over the five-year period. Everyone will be told thatthey are free to leave at any time during the experiment and that nopsychological damage will occur during this experiment. After thebriefing, the groups will be taken to the indoor range and shown thesigns in normal indoor lighting from overhead fluorescent lights.They will be taken through the range one at a time and asked to namethe fifteen (15) signs, each of the five at three differentdistances. The first cycle through will be at twenty-five (25) feet.The order of the signs will then be randomly switched up and thesecond cycle will be at fifty (50) feet. The random placing of thesigns will again occur and the participants will be walked throughagain, this time looking at the signs from one hundred (100) feetaway. Each cycle will be videotaped and recorded by a lab technician.The lighting for each group and each cycle is held constant, as isthe temperature. After the sign identification tasks, theparticipants are taken into the front conference room and givenpaperwork and a contact number so that they can check up on theexperiment if they choose to do so. They are then debriefed and givena meal consisting of a sandwich and a cola of their choice for lunchto show them that they and their efforts are appreciated. The resultsof that group are then saved onto a computer and three (3) back-upcopies are made. One is stored in the file cabinet in the office atthe range. One is put in my brief case for safe keeping, and thethird is taken to a safe deposit box for storage until the data isneeded for analysis.
Once all four hundred (400) participants have been run, The datawill all be compiled onto a spreadsheet. Means of the informationwill be calculated and several analysis will be done. First a T testwill be run and then an 3x4x5 between subjects Anova will be done.After that, A Pearsons r will be run to see if there is anycorrelation between the categories. If so, a Tukey test to determinethe extent of the correlation will be run.
After the year for this study is up, the trichromatic controlgroup will have distinguished the signs best of all. This follows thehypothesis that because this research is designed only to find a wayto bring dichromats up to the level of normal trichromats in theability to read the signs. Tritanopia sufferers will have mostproblems distinguishing between signs. Therefore, signs are neededthat can be distinguished more by them than the other two. Sincethere is a noticeable difference in the ability to distinguish thesigns depending on ability to see color and the distance, the nullhypothesis will have to be rejected and more research will need to bedone in order to find signs which will be seen well by all.
Now that it is known how well different business signs can be seenby different color deficient people, several new steps must be takento further the knowledge base. The first step is to design anexperiment which will let a material and a color or series of colorswhich can be easily seen by all dichromats and all trichromats. Signswill be constructed of varying shapes and use different series ofcolors depending on their purpose. Hopefully, within a few years ofdevelopment, the new signs will replace the old style sign and theusefullness of road side advertisement will increase. More researchwill be conducted at the close of this experiment. Hopefully, usingsome combination of colors easily contrasted by dichromats andtrichromats alike, a new form of sign can be developed that possiblewill light up the words to give them greater contrast, or reflectivepaint can be used to cause the meaning of the sign to stand out moreprominently. Perhaps, like the "STOP" sign, an easily discernableshape can be made for each sign type. Perhaps a more drastic degreeof separation is needed.
Further into the future, I would like to lead research anddevelopment into the design of signs which will make it possible foreven monochromats to see easily. Hopefully, within twenty (20) yearsfrom the close of this research, a team of professionals will be setto work designing and developing signs which will allow all but thetotally blind to see it and know what message it carries.
Color. Retrieved from http://www.colorforum.com/ April 2002.
Color and Color Vision. Retrieved fromhttp://www.yorku.ca/eye/color.htm April 2002.
Color Blindness or Color Deficiency. Retrieved fromhttp://www.allaboutvision.com/conditions/colordeficiency.htm April2002.
Crone, Robert A. (1999). A History of Color. The Netherlands.Kluwer Academic Publishers.
De Reuck, A. V. S., and Knight, Julie (Ed.). (1965). ColourVision. Boston. Little Brown and Compan
Delman, Howard Mark. (2001). ìA comparison of visualfunctions between color-normal and color-deficient observers.îDissertation Abstracts International: Section B: The Sciences &Engineering, Vol. 62, 3-B.
Goldstein, Bruce E. (2002). ìPercieving colorîSensation and Perception. Library of Congress. USA.
Motokawa, Koiti. (1970). Physiology of Color and Pattern Vision.Hongo Bunkyo-ku, Tokyo. Igaku Shoin.
Neitz Color Vision Lab. Retrieved fromhttp://www.mcw.edu/cellbio/colorvision/ April 2002.
Padgham, C. A. and Saunders, J.E. (1975). The Perception of Lightand color. New York. Academic Press.
Snape, Lindsay T. and Jeagle, H. (2001). ìI used to becolor blind. Color Research and Application Vol. 26, 269-272.
The Rods and Cones of the Human Eye. Retrieved fromhttp://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html April2002.
Trichromatic Theory. Retrieved fromhttp://www.yorku.ca/eye/trichrom.htm on April 2002.
YOUR TITLE. Retrieved fromhttp://serendip.brynmawr.edu/biology/b103/f01/web2/baird.html April2002.