Ishihara plate No. 13: You probably see the number "6", but I see nothing. (Image: Public Domain)

Students interview me about my color-blindness

I know a high school teacher who teaches science and had just finished a unit on sight and genetics with her students. She asked me if I’d like to be interviewed by her ELL students in class one day. Before I came to class, she asked her students to think of some questions, and then they each selected one to ask me while I was there (she told them ahead of time that I was an artist, so they were really interested in that). The students were already familiar with Punnett squares so we did those on the whiteboard.

It was a really fun and interesting experience for all of us, so I kept a copy and wrote my answers for others who may be interested. (Student names are changed).

Ishihara plate No. 13: You probably see the number "6", but I see nothing. (Image: Public Domain)
Ishihara plate No. 13: You probably see the number “6”, but I see nothing. (Image: Public Domain)

Josephina: Were you born color-blind?

Yes, I was born color-blind. Color-blindness is caused by a person’s genes, which they inherit from their parents before they are born. So there is no way for someone with typical color vision to later become color-blind later in their life.* There is also currently no way to cure color-blindness, so I will be color-blind my whole life.

However, being a woman who is color-blind is pretty rare: color-blindness affects about 1 in 20 males, but only 1 in 400 women. Color-blindness is a sex-linked trait, which means that the genes are on the sex chromosome X. Males and females are affected differently because males only have one X (XY), but females have two X’s (XX).

If a boy inherits an X with a defective color vision gene (X`), he is color-blind because he has only that copy of those genes. A girl can inherit an X with a defective gene, but she can still have normal color vision because the effective gene on her other X chromosome will compensate for the defective one. In order for a girl to be color-blind, she has to have two copies of the mutated gene (X`X`), which is why it’s so rare.

Jan: What colors can’t you see?

The term “color-blindness” is not completely accurate. I can see all the colors, but I do not see them as well as people with typical vision see colors, or I have trouble distinguishing between two similar colors. For example, purples might look like blue to me, or certain greens and browns may look the same.

Sometimes color-blindness is called “color vision deficiency” because the condition comes from a deficiency in one or more of the cones in the eye. There are three cones in the eye that different ranges of color, and my understanding is that the cones that are most sensitive to red colors is defective,

Berny: When did you learn you were color-blind?

I learned that I was color-blind at a very early age because my parents knew that there was a chance I could be color-blind. The eye doctor gave me the Ishihara test for color-blindness [of identifying numbers from an image composed of dots], and it indicated that I had a type of color-blindness called “red-green color-blind.”

My mother’s father (my grandfather) was color-blind, which means that my mom has one normal gene and one defective gene, and her genotype is XX`. She’s called a “carrier” because, although she herself is not color-blind, she can “carry” the color-blind gene to her children. My father is color-blind, so his genotype is X`Y. To find out the chances that I would be color-blind, we can use a Punnett square (shaded gray indicates a person who is color-blind):

Punnett square cross between a female color-blind "carrier" and a color-blind male (CC BY Hillary Lauren).
Punnett square cross between a female color-blind “carrier” and a color-blind male (CC BY Hillary Lauren).

The ratio of probability is 25% non-color-blind girl, 25% color-blind girl, 25% non color-blind boy, and 25% color-blind boy. Or in other words, regardless of whether I was born a boy or girl, there was a 50/50 chance that I would be color-blind.

Jorge: Do you have any siblings who are color-blind?

Yes, I have a twin sister, and she also happens to be color-blind. So, of all the people in my immediate family, my mom is the only one who is not color-blind. She thinks it’s funny when she has to settle an argument on the particular color of a car.

Mimi: How did you feel when you learned that you were color-blind?

Perhaps because I learned about my color-blindness at an early age, I was not upset because I just accepted it as part of who I was. There are some things I knew I could not do because of my color-blindness, such as becoming a commercial airplane pilot. But, my color-blindness also didn’t stop me from becoming an artist!

I’ve never had typical color vision, so I can’t compare how “my” world compares to the world other people see. But, if I’m missing out on anything, I can’t tell or it doesn’t really make a difference. Besides, being a color-blind woman is unique and I enjoy learning about it and talking to others about it.

Lucita: Do you think your kids will be color-blind? Why?

If I have kids, there is a chance they will be color-blind, but it depends on who their father is and whether he is color-blind or not. We can solve this problem using a Punnett square again.

So this is me, with the double color-blind chromosomes X’X’ and a color-blind man with X`Y.

Punnett square cross between a color-blind female and color-blind male (CC BY Hillary Lauren).
Punnett square cross between a color-blind female and color-blind male (CC BY Hillary Lauren).

All of our children would be color-blind! This is because they would only inherit X’s that have a mutation. Let’s look at another Punnett square for a father that had typical color vision (XY).

Punnett square cross between a color-blind female and male with typical color vision (CC BY Hillary Lauren).
Punnett square cross between a color-blind female and male with typical color vision (CC BY Hillary Lauren).


So, if I ever have a son, he will be color-blind: he would inherit the X` of his XY from me, and I could only give him X’s with a defective gene. If I had a daughter, she would be a carrier, because one of her X’s would be from me, and the other (normal) X would be from her father. She would have normal color vision.

Allie: Who helps you identify colors?

Everyone! When I create art, I will ask my coworkers to double check the colors I have used to make sure I have not accidentally make something that was supposed to be gold actually a yellow-green color, for instance.

My friends will help me notice certain flowers on a hike that I wouldn’t otherwise notice. Once we were in the woods and they were like, “Wow! Look at those beautiful orange flowers on that tree!” It was in the distance, and I couldn’t see it at all. But, after they were able to help me exactly which tree they were talking about, I could see the orange flowers that they had noticed immediately.

When I’m by myself, I will even ask strangers to double check colors for me in the store, to make sure I am buying blue sheets instead of purple sheets, for example.

Natelli: Is it hard to identify the colors of your clothes?

In the past, there have been times when I was convinced I had a pair of brown pants and they were actually a green color, and I didn’t find out until much later when I said something about “my brown pants” and my friends were confused and corrected me. (Laughs). Now that doesn’t happen so much anymore because I think colors that are easy for me to see are more appealing to me. I’ve wondered if this is related to my color-blindness–I wear a lot of blue because I think it is appealing and has a lot of variations. I also wear a lot of grays and blacks with some bright colors. But, my color-blind sister prefers to wear much different things than me, so it’s probably just personal preference.

Han: How do you draw a beautiful picture? What are problems that you have when you draw a picture?

I have trouble matching colors. One time when I was in high school, I was painting a picture of a cloth that was tan with brown stripes. I ran out of paint, and when I went back to mix more paint, I accidentally used a dull green-brown color instead of brown. My teacher caught my mistake, but I had to go back and correct the green parts to brown using the correct paints.

Bobbi: How long have you been driving? Is it difficult because you’re color-blind?

I have been driving since I was sixteen years old. There are certain challenges to driving as a color-blind person, but there are ways to compensate for it. For example, a light signal has green, yellow, and red colors, and sometimes it can be difficult to distinguish the yellow and red colors. However, I know that the green light is on the bottom and the red light is at the top, so I can distinguish those. Some countries have extra cues to help people with color-blindness, like having different shapes for each of the lights or adjusting the colors so they are more easily distinguished.

Alfredo: What other things are difficult to do because you’re color-blind?

This didn’t happen to me, but someone I know once had difficulty doing his job because he had to read text on a computer screen that had different colors instead of just black on white background. He was fired and one of the reasons they gave is that he was not able to learn to use the computer very well. Even though he had asked them to change the colors on the screen, and it was possible to do so, they had refused to change it. To make a long story short, he took his employer to court and the case was picked up as a discrimination case, because color-blindness is considered a mild “disability.” Eventually he won and was able to get compensated for lost wages.

Thank you for your questions, this was a lot of fun! I hope you were able to learn something from me.

– The Science Slug


Additional information

*After doing additional research, it turns out that it is possible to acquire color-blindness later in life:

References and links used in this post

New direction for the blog

It’s been quite a while since I’ve posted, mostly because my life has been pulling me in directions other than thinking and writing about science. I’ve been doing a lot of design, especially, and I’ve wanted to share my projects with the world, but I haven’t had the venue for it. So I’ve been thinking lately that I should expand the scope of this blog to include more of my interests: science, education, games, and design. Of course, the Science Slug will still be the beloved mascot!

I’m really excited for this new direction and to start posting again! See you soon,

The Science Slug

Thinking about the Big Bang blows my mind

As an illustrator who’s dabbled in animation myself, I love the science videos by Kurzgesagt, who has just recently posted a new video on “The Beginning of Everything: The Big Bang.”

Besides the appealing graphics and Hitchhiker’s Guide-esque narration, a few things struck me about the video. One I’ll mention here is this almost casual observation: “But what’s the meaning of ‘light’ anyway, when there’s nothing alive yet that could have eyes?”

Since light and sight are so central to how humans function in the world, it’s easy to forget that “visible light” (commonly just “light”) is only called that because it’s the miniscule part of the electro-magnetic spectrum that our eyes are capable of detecting. There are numerous species who have more complex eyes than we do and can see more of the light spectrum, like mantis shrimp (Order: Stomatopoda). There’s much much more “unvisible light” in the Universe, from radio waves to gamma rays, that has been (and still is) bouncing around for millenia all over the galaxy. And we only experience just a tiny, little sliver of that time and spectrum, but we’ve learned so much already! And so much left to explore!

“Since we ourselves are made from dead stars, we are not separate from the Universe. We are part of it. You could even say that we are the Universe’s way of experiencing itself.” When one contemplates the Universe, and one’s place in it, you can’t help but be poetic.


Matters of the head and heart

In a study published online on Feb. 10 in the Proceedings of the National Academies of Science (PNAS), researchers at the Institute for Systems Biology and the U.S. Army Center for Environmental Health Research present molecular evidence that exposure condition similar to that experienced in posttraumatic stress disorder (PTSD) can cause heart tissue damage in mice. Continue reading


Best way to get kids to like science? Inspire teachers

Science teachers and principals from Schmitz Park and Arbor Heights Elementary Schools in West Seattle attended a day-long workshop co-hosted at the Institute for Systems Biology. During their visit to ISB, the educators were enthusiastic to collaborate, learn about new curriculum materials, and see first-hand what an innovative science research space looks like at ISB.

“The day signified much more than these teachers learning about some instructional materials,” said Dan Gallagher, the Science Program Manager for Seattle public schools. “Two different schools, with both principals side by side, working together on their desire…to improve science education for their students is pretty awesome.” Continue reading

tumor paint

Lighting up a new way to treat pediatric brain cancer

Dr. Jim Olson, a physician at Seattle Children’s Hospital and research scientist at the Fred Hutchinson Cancer Research Center, likes to share stories of the patients and people in his life who provide a motivation for his research on brain tumor treatments.

At a recent Town Hall presentation, Olson shared a recent experience about his own mother, who was receiving radiation treatment for a cancer at the base of her brain. The physicians were attaching a metal frame the size of a football helmet to her head “the same way you would attach a Christmas tree stand to your Christmas tree,” by turning screws on the frame until they touched her skull and stuck. Continue reading

Ants act like a liquid or solid

Researchers at the Georgia Institute of Technology presented their research on the physics of how fire ants (Solenopsis invicta) cling together to form a living “material” that can have the physical properties similar to liquids or solids. Because their underground nests in the wild can be flooded in the wild, the ants have this survival-mechanism behavior to form rafts that float on the surface of water.

> Read the article in the New York Times.
> View the abstract for the presentation from the American Physical Society.
> See more videos of the ants forming water rafts (Nathan Mlot, Georgia Tech).

Whale shark at the Georgia Aquarium (CC BY Hillary Lauren).

Whale sharks and the ethics of aquariums

I was in Atlanta, Georgia, last week for a conference and had a few hours to do something for fun around town. I decided to go to the Georgia Aquarium. Besides the fact that it was highly recommended, I heard that there were whale sharks there, and when I knew that, I had to go. I had seen whale sharks once before in Osaka, Japan, when I was a teenager, and I had thought it was the only time in my life I would see one. Continue reading

The Hive Queen by morganagod.

Ender’s ants

As a childhood fan of the book, I couldn’t help but see the movie Ender’s Game last week. For a book adaptation, I thought the movie did a really good job. I could go on, but this is a science blog, not a movie review blog–the point is, while I was watching I noticed a great science learning opportunity!

Ender’s Game follows the military training of a Ender Wiggin, a boy with promising talents as a military genius. Set in the future, Earth has almost been destroyed from a war with an alien species, known as the Formics or “Buggers,” and is now preparing to retaliate. Continue reading

N. fowleri as a cyst, an amoeboid blob, and with transportive tails. Public domain, CDC.

Zombie amoeba

Whether you went trick-or-treating or stayed at home watching scary movies for Halloween, you probably saw some monsters during the holiday. But did you miss the monster that can be described as a frightening mix of a zombie, a werewolf, and The Blob?

Enter Naegleria fowleri, the brain-eating amoeba! Although not many people have actually ever seen this microscopic “monster,” it can still pack quite a punch: the fatality rate for someone infected with this parasite is 99%.

What is this little creature? Should we really be worried about the Zombie-Amoeboid Apocalypse? Let’s investigate… Continue reading