The book Colour Blindness: Causes and Effects was written by Donald McIntyre in 2002. It is a great introduction for the general reader into the topic of color vision and its deficiencies, and discusses many different topics related to color blindness.

Donald McIntyre is colorblind himself and was in contact with many people doing research into color vision and color vision deficiences while writing this book. He compiled an excellent overview with many up to date details about the latest findings in the field of color vision deficiency.

The book is split into two equal parts, starting with the basics of color vision in the first part: The causes of Color Blindness. This part also includes a detailed overview of the different types of color vision deficiency and descriptions of some color blindness tests, which can be used to identify and classify your specific deficiency.

In part 2: The effects of Colour Blindness, McIntyre asked himself: “What is it like to be colorblind?” He researched different areas and has some answers ready for you, fitting into the following four chapters:

The appearance of colours: including a discussion and samples of how colorblind people see the world.
Everyday life: about art, sport, food and more, and the awareness of a color vision deficiency.
Careers: a great overview with some detailed information on professions and their suitability to color blindness.
Techniques that may help: like the Seekey or colored contact lenses.

There is one point concerning the book which I think could have be done much better: The Bibliography. The book provides a huge source of detailed information on almost every topic attached to color blindness. But when it comes to the sources of those information the author fails. In a book which acts like a well prepared aggregation I’m also expecting a very comprehensive list of sources to get deeper information if I would like to learn more about a specific topic.

Overall Colour Blindness: Causes and Effects is a great and easy readable book about color vision deficiency which I recommend everybody interested in the topic. Not only if you are colorblind yourself, but it can also be a great source of information for parents, spouses or teachers.

You can also visit the books homepage at www.daltonism.org.uk.

How Many Colors Can You Name in Five Minutes?

February 1, 2008

@colblindor

Tools No Comments

I suppose I could have done much better in this quiz, if I would have checked my own tool Color Name & Hue before I tried my best.

And I guarantee you, if you remember just a bunch of the 1640 different color names which are listed in Color Name & Hue, you’ll perform much better than me.

I just tried the How Many Countries Can You Name in Five Minutes and did much better. In the end they counted 43—and 227 remaining…

Color Vision Guide – A Fact Sheet on Color Blindness

January 29, 2008

@colblindor

Publications 1 Comment

The Color Vision Guide gives you a brief introduction to color blindness on a single sheet of paper. You could also call it a perfect starter for anybody interested in the topic of color vision deficiency.

About 14 years ago John Nash together with his brother and their mother created a guide to educate people about color blindness. He is suffering from green-weakness (deuteranomaly) himself and wanted to share his knowledge with others.

The guide includes the following parts, putting together a well designed sheet of information on color blindness:

Biological background of color vision and its diseases.
Jobs and color blindness.
The inheritance pattern of red-green color blindness.
Distribution diagrams of the three different color vision deficiencies.

On top of that the Color Vision Guide includes a small set of Ishihara color blindness test plates, which can be used as a basic check for red-green color vision deficiency. Well done.

John is also writing about different aspects of color blindness on his recently created weblog at the Color Vision Store. If you visit him, say hello from Daniel :-)

The Ishihara Unicorn Shirt

January 18, 2008

@colblindor

Children 3 Comments

Last December Nick offered 50 free shirts with an imprinted Ishihara like unicorn image. They were all given away to colorblind children for free.

He was so kind to send me also two of them for my two little toddlers. As you can see, the shirt is still a little bit to large for my boy.

I showed the shirt to my son and asked him: “What do you see?” His answer was of course: “A horse.” What else dad?

If I look at the image I can see only trees—and a lot of dots. Thanks Nick.

Does Color Blindness Disqualify from being a Firefighter?

January 15, 2008

@colblindor

Professions 12 Comments

It is quite well known that a lot of police officer applicants are disqualified by their color blindness. But what about if you would like to become a firefighter and you have a color vision deficiency? Do the same rules apply?

I’ll share my thoughts with you after the following personal story I received by a reader of Colblindor.

I’ll give you a bit of history on myself. I have recently taken schooling to become a firefighter, and seem to have run into a wall due to a color deficiency which I have. Funny things is I went to an ophthalmologist about 2 years ago and was cleared for the D-15 test with 0 errors.

But the next time I took it I convinced myself that it was suppose start with blue and end in green as the doctor did not say it was to fade into red. For some reason thats what I thought it was the last time I took, while I was doing it though I knew it was incorrect. When the doctor pulled it from me obviously it was horribly wrong. So he sent me for further testing during which i did D-100 plus lantern. The D-100 I used one eye at a time and it was difficult. End result I have been diagnosed with severe color blindness. And yet I can do the D-15 online with 0 errors and the confusion test with decent results as well as 1 wrong in ten.

Wondering where you might recommend getting some solid answers as there seems to be a lot of ignorance in the medical field and the fire department. I went through fire school with no problem, as well as the rest of the courses I took with no problems what so ever, and now they tell me that my colorblindness is a hazard. Anyway, right now I am quite frustrated and looking for answers as this is what I want to do—yet I feel that I being discriminated based on ignorance of color blindness.

Now this sounds pretty unfair. You accomplish everything just perfectly and only your color blindness should disqualify you to become a firefighter?

Has color any importance for firefighters?

As you know every fire has its color or better said consists of a whole range of colors. The colors not only tell us something about the burning substance but also are very closely related to the heat of a fire. For example a red fire can have a temperature between 977°F (525 °C) with a just visible red and 1830 °F (1000 °C), a cherry, clear red.

Also smoke has a color which can tell you a lot about the elements making up the smoke you see. And as any smoke can be very heavily toxic it is important to be able to distinguish different shades of color. At different stages of a fire the smoke color changes and therefore it is important for a firefighter to be able to interpret colors appropriately.

This are only two reasons why good color vision can help you to be a professional firefighter.

How firefighter applicants are tested for color blindness.

Often a standard test will be used to test if you have good color vision or not. Some type of Ishihara plates are very well known and often used. But you could also come across any type of arrangement test or a simple lantern test.

If you look at the following recruitment information of three different Fire and Rescue Services, you will see that it is very common to ask for good color vision. But the rules for color blindness can differ between the recruitment centers.

Hampshire Fire and Rescue Service
The minimum standard accepted by HFRS is the Farnsworth D-15 standard test.
Shropshire Fire and Rescue Service
You must have an appropriate level of colour perception, if you are found to be colour blind, we will send you for more tests to determine if you can work safely in a safety critical environment.
Devon and Somerset Fire and Rescue Service
Potential firefighters are subject to certain entry requirements specified by law. Applicants should be aged 18 and over; have good eyesight, not suffer from colour blindness.

NFPA: color vision deficiency doesn’t disqualify you

In the latest edition of the Standard on Comprehensive Occupational Medical Program for Fire Departments (2007 Edition) published by the National Fire Protection Association the rules concerning color blindness have changed. The following Report on Proposals makes it clear, that a color vision deficiency doesn’t disqualify you anymore from being a firefighter.

Formerly, color vision deficiency was listed as a Category B* medical condition. However, it is felt that within most cases this condition will not affect the ability of a member to safely perform the essential functions of his or her job. The fire service physician should consider the color vision deficiency of the individual and consider the color vision requirements of the member’s job and reach an individual determination.

*Category B: A medical condition that, based on its severity or degree, could preclude a person from performing as a member in training or emergency operation environment by presenting a significant risk to the safety and health of the person or others.

How to apply as colorblind firefighter

First of all you shouldn’t just forget about becoming a firefighter just because you have any kind of color blindness. As written above there are many different rules used and views are changing for the benefit of colorblind applicants.

So if you apply just be honest and tell them the truth about your vision. It won’t help you if you try to hide it or cheat on certain tests, because most often it will strike back and you will be looked at as an unreliable person. I would tell them about your color vision deficiency from the first moment on.

Then you can take the test and see what happens. If you pass, that’s perfect. And if you fail and they won’t let you go one step further just because of your color blindness, you should ask for precise explanations and try to describe them, how you see the world and how this could handicap your work as a firefighter.

Of course it could help you if you tell them about the most recent NFPA Report 1582 (see above) and their changed view on color blindness.

Maybe discussing color blindness at FirefighterNation.com, or other places, could also help to get the topic of color vision deficiency more recognized at recruitment offices, which will help all colorblind colleagues which would like to become a firefighter.

Fire! Picture taken by Wili Hybrid.

Color Blindness Tools —
Color Name & Hue

January 11, 2008

@colblindor

Tools 1 Comment

I’m proud to announce my first color blindness tool. Up to now Colblindor was a growing resource of information about color blindness. With this step I would like to go further and start offering tools related to color blindness.

Those tools shall aim for the following two goals:

Help colorblind people to accomplish certain tasks.
Achieve a better understanding of color blindness among non colorblind people.

My first tool which I am releasing today is called Color Name & Hue and it will help you to categorize colors into the main hues Red, Orange, Yellow, Green, Blue, Violet, Brown, Black, Grey, and White.

This tool offers you the following possibilities to find a certain color: either you just browse the color space with the sliders or you enter RGB, HSB or Hex values.

Color Name & Hue will find the closest matching named color among a list of 1640 colors. It will also match this color to its corresponding main hue.

By the way, I compiled the list of colors out of different sources which can be found on the web. Unfortunately not everybody agrees about certain hues so it wasn’t an easy task to find the correct hues. If you find any colors which are definitely matched to the wrong hue just let me know.

I hope you like the tool and it would be interesting to learn in which situations you can use it.

A Gift for the Colorblind

December 2, 2007

@colblindor

Children 9 Comments

Nick is wrapping the project up. All of the shirts were spoken for and the project was a great success for him. I’m sorry if you couldn’t get one of the shirts for your son or daughter.

Colorblind Shirt Unicorn

Greetings,

My name is Nicholas and I am a grad student at the School of Visual Arts MFA design program in New York City. I have created a color blind pattern for t-shirts that I hope to distribute to young children. The shirts are free for children who have recently found out or have known for some time that they are colorblind. In my own experience I have found that those with no deficiency in color vision often misconceive color blindness as a warped perception of reality. Such is not the case.

So, I have made these shirts to celebrate color blindness and the magical world that the color blind see. In this example, an image of a forest is clear to all, however the unicorn within the forest is only visible to those with normal vision. Actually seeing a unicorn is of course much sillier than being color blind. That which the colorblind see in this world may be more spectacular then one could ever imagine.

This is a one time extreme limited run of 50 shirts with a six color screen print. Sizes run youth medium – adult large. Please specify for whom the shirt is and what size. Once the 50 are gone, I will never print them again.

Also, if you could send a photograph (any quality and doesn’t even need a face) of someone wearing the shirt once received it would be much appreciated.

Improving the Readability of Public Transport Maps for Colorblind Travelers

November 7, 2007

@colblindor

Publications 1 Comment

Report Cover — Color blindness friendly coloring of public transport maps.

A group of students from the Norwegian University of Science and Technology decided to make a project work about color vision deficiency. In detail they developed guidelines on how to colorize bus or subway maps taking color blindness into account.

The interdisciplinary group had ten male colorblind test persons and based their findings on the maps of London, Oslo and Trondheim.

First of all the test persons were examined on the type and the severity of their color blindness. That for the students used a set of Ishihara plates and a Lanthony arrangement test.

After that the examination was split into several different tasks like…

…testing which colors look the same to each test person,
…which are the problem areas of the maps,
…and also which colors would the most likely be able to distinguish on a map.

The columns of the table to the right show the different bus line colors of Trondheim. The rows are linked to the test persons and the different marks show line colors, which looked the same to the person under test.

It is very interesting to see that firstly, every person had at least one pair of problem colors, and secondly that they are often the same but sometimes can be quite different.

In the end of the report the study group formulates a set of guidelines which should be followed to increase the readability of public transport maps.

Make stylized maps without to much geographical information. This will ease the readability since it makes it more easy to separate the different lines.
Use white frames around the lines since this helps keeping the colors invariable and reduces the confusion when the lines intersect.
Use thick lines. Through this the eye can interpret the color better.
Mark the lines with numbers, especially when the line intersects with others and splits.
Variate the intensity of the colors. The intensity differences are also visible for persons who are colorblind. Choose therefore to use colors with distinct intensity differences. Specially when using similar colors and color combinations, which some people could see as one color. For example:
- Brown, red/pink, green
- Grey, red/pink, green
- Blue, purple, red, pink, green

“Our opinion is that these guidelines will make public transport maps more easily accessible for people with color blindness, and should be possible to implement without reducing the readability for people with normal vision.”

If you are interested the report is available only in Norwegian as PDF download: Fagrapporten.pdf (8MB).

How does a Total Colorblind Child’s Future look like?

November 5, 2007

@colblindor

Children 2 Comments

Total color blindness—also known as complete color blindness or monochromacy and with the scientific name achromatopsia—is very uncommon. Less than one out of 30’000 people is affected by this special form of color vision deficiency.

What if your son or daughter suffers from complete color blindness, how might a possible future look like to your child?

I just came to know my sister’s son is total colorblind. He is 12 years old.

Since he is total colorblind, does it mean he sees all color in monochrome gray shades or can he see some of the colors?

What kind of profession should he pursue since he is total colorblind?

Is it fine for him to get work as a software engineer or a doctor?

Is it fine for him to drive when he grows up?

Before answering the above four questions I would like to say a few words about complete color blindness. A young baby suffering from monochromacy will start to twinkle in bright light. Why? Because all cones which are needed for color vision and day vision are absent and therefor vision is solely based on rods. This receptors can’t see colors and are responsible for night vision. This means they are very sensitive to bright light which additionally leads to very poor visual acuity.

This means, if your child really suffers from complete color blindness he or she…

…needs strong sunglasses in normal daylight.
…has poor visual acuity.
…also suffers from nystagmus (nervous eyes).

1. Does he see all color in monochrome gray shades or can he see some of the colors? If you are suffering from achromatopsia you can’t perceive any colors beside black, white and fine tuned shades of gray. There is no feeling or sensation of color at all.

2. What kind of profession should he pursue since he is total colorblind? Unfortunately complete color blindness can be a huge handicap in many professions. But there are many people who showed that also a huge variety of jobs can be done with this deficiency, like Dr. Nordby an internationally recognized vision scientist, lecturer, and writer. You can find more personal job stories in the book Living with Achromatopsia.

3. Is it fine for him to get work as a software engineer or a doctor? To work as a software engineer should cause no insurmountable hurdles. Of course you might need an extra large display and adjust some color settings. But programming is a logical and not a color related job. To work as a doctor could be tougher. A doctor needs good eyesight during his work and also needs to make decisions based on colors. There might be some work which can be done as a complete colorblind person, but it won’t be easy at all.

4. Is it fine for him to drive when he grows up? Unfortunately I have to tell you that you can’t drive when you are suffering from achromatopsia. The handicaps I described above are just to big to be able to safely drive a car.

Please make sure that you also visit the very comprehensive site from the Achromatopsia network. They are also offering two books as pdf download with a lot of specific information on this very special type of complete color blindness: Understanding and Coping with Achromatopsia and Living with Achromatopsia.

Seekey – Colorblinds See Otherwise Invisible Colors

October 31, 2007

@colblindor

Tools 1 Comment

Are you red-green colorblind? Do you have a handy tool in your pocket which helps you in critical situations to tell certain colors apart? If not you might like to learn more about a tool called Seekey, which exactly can do that for you.

Seekey is a little tool consisting of two different light filters: a red and a green filter. Looking through them will change the way you perceive the color of the object you are focusing on. Based on the difference in color perception through the filters and without filter you can guess the correct color.

Let us have a look at a little example: It is always very tough for a red-green colorblind like me to spot the nice orange blossoms in our green garden. Those two colors just look so similar to my eyes. With Seekey this changes. Looking at the blossoms through the red filter, they get lighter while the surrounding green darkens. The green filter changes the effect and lets all the green lighten up compared to darker blossoms.

There are several color keys coming along with Seekey. Through those color keys you will learn how the color perception changes when looking through one of the two filters. The table to the left shows you an example for the colors red, green, orange and brown.

Kenneth Allblom is the inventor of Seekey. He is living in Sweden and distributing the tool either directly through his web page or otherwise it can be bought at opticians and in certain boat equipment stores in Great Britain, France, Sweden, Finland, Germany, New Zealand and Japan.

A study at the Karolinska Institutet in Stockholm Sweden even showed that the Seekey tool will assist red-green color deficient persons to achieve an 86% improvement at the Ishihara test for color blindness.

Seekey is a handy tool which can help every red-green colorblind person. Visit the Seekey homepage directly to get more detailed information about this little helper.