A chromatopsia. Tritinopia. Monochromacy. That's a lot of words. Worried you don't know what they mean? Well, good news by the end of this episode, you will know for sure because it's the colorblind episode. I'm Mimi Fotz, and this is Hello from the Van. What does it mean to be colorblind? Colorblindness affects nearly one in 12 men, about 8% of the general population, and 1 in 200 women, that's about half of a percent of the general population, and there's no cure for it. But what is it? To be colorblind or color vision deficient means that a person doesn't see colors in the same way that the majority of the population does. But before we can explain this major group, we need to explain how your eyes perceive color. The human eye sees three basic colors: red, green, and blue. These are the primary colors of light. You may have learned that the primary colors are red, yellow, and blue. There's even a song about it. Yeah, that song only applies to art and painting. Light and science use different primary colors. Here's why. If you mix the primary colors of red, yellow, and blue, you will get a dark, almost black color of paint. However, if you mix red, green, and blue colored lights together, you will get a bright white light. The sum of their parts are opposites. Pretty cool, huh? So let's get back to our eyes. Our eyes require light to see. It's going to get a little neurosciencey here for a second, but hang with me. In your eyes are things called photoreceptors. These are the parts of your eyes that process the light around you, then send a signal to your brain that tells you what you're seeing. They are called rods and cones. Rods are sensitive to light and dark. Have you ever walked from the bright outdoors into a dark house and it takes a second for your eyes to adjust? That's when your rods are working overtime. Your rods are what help you see at night. They're great at night vision. However, they are terrible at color because color is handled by the cones in your eyes. The cones are not as sensitive to light as rods. However, cones can perceive green, red, and blue. But here's the catch. That's why you can't see color very well in dark places. An easy way to remember this is I always think of a curtain rod. A curtain rod opens the blinds and lets in the light into your house. It's the same with your eyes. The rods in your eyes let in the light, and the cones let in the color. To give you an example of this, have you ever colored a picture, then taken it into a different room and the colors look different? Yep, you can thank the brightness of the light and the cones in your eyes for that. This is what makes picking house paint such a pain. Colors change depending on the intensity of light. Now that we know how our eyes perceive light, let's talk about the why. Why are some people colorblind? Well, those with colorblindness normally have problems with the cones in their eyes. It's a sliding scale. Not everyone with colorblindness has the same exact type because everyone's cones are different. That's why the term colorblindness is sometimes referred to as color deficiency, because not everyone is fully colorblind. Again, it's a sliding scale. There are two types of colorblindness or color vision deficiency. Those two terms are different and it's a matter of exactness of language. True colorblindness is called monochromacy and means that the person who has it can only see the world in shades of gray. This is true colorblindness, as those with monochromacy can't see colors at all. In essence, they view the world as if it's the black and white scenes in Kansas at the beginning of The Wizard of Oz. This condition is very rare. It's rare enough that meeting someone with it is normally a once-in-a-lifetime experience for a lot of people. Blue cone monochromacy affects about one in every hundred thousand people. This means there are less than 82,000 people in the entire world with this condition, and most of them are men. So if you meet one, just know that it's super rare. They're a unicorn! So we've talked about true colorblindness. That's when someone has monochromacy. But what does it mean to be color vision deficient? Let's talk about that. It's called dichromacy, and it is basically an umbrella term for several different versions of color deficiency. We use the term colorblind because it's a convenient way to say color difference. Now here's the neuroscience-y part. We have three colors of cone receptors in our eyes: green, red, and blue. They match up with the primary colors of light. Different types of colorblindness are dependent on which color of cone receptor is working. In monochromacy, mono meaning one, only one color of cone works. In dichromacy, only two colors of cones work. But we have three colors of receptors in our eyes. That's why there's different types of dichromacy. People with protonopia or protonopia are unable to perceive any red light. Those with deuteronopia are unable to perceive green light. And those with tritinopia are unable to perceive blue light. Different cones, different colors. But let's talk a little bit more about the specifics of each of these types of colorblindness. What is the real life implication for the people who have this condition? First, we're going to talk about tritinopia. This means that they have a reduced sensitivity to blue light, and despite the description, tritinopia does not make it difficult to tell the difference between blue and yellow, but colors that contain blue or yellow. The difficulty for them lies between colors like green versus blue, or yellow versus pink, or purple versus red. Now, tritinopia confuses color perception, and colors may seem less bright, but it does not affect clarity or sharpness of vision. Meaning it's possible to have perfect 2020 vision and have tritinopia. They're mutually exclusive. I asked around to see what those with tritonopia struggle with on a daily basis, and apparently it makes it very difficult to read maps, as the colors blue, green, and yellow are regularly used for physical and digital map making. I'd never even considered that before, but it is genuinely a very difficult struggle. Aside from tritinopia, known as yellow blue colorblindness, there is also red-green colorblindness. This comes in two different forms: protonopia and deuteranopia. In either case, it is red-green colorblindness. If you would like to experiment for yourself to experience just a little bit of what it feels like to have red-green colorblindness, simply find a pair of yellow sunglasses. These are sometimes called driving glasses or night glasses. I found some at my local dollar store. What you're gonna do is you're gonna put on these yellow sunglasses and try doing a couple everyday tasks while wearing them, such as coloring or writing in different colors of pencil, or even something as simple as doing the dishes. This will give you a little bit of an experience of what it is like to have protonopia and deuteranopia. Outside of yellow-blue colorblindness, red-green colorblindness comes with its own set of challenges. Let me give you an example. What are the common colors in a traffic light? Red, yellow, and green, right? And if you have red-green color deficiency, do you see where I'm going with this? It can be easy to confuse the colors on a traffic light. Add in the position of the lights, and you have a recipe for disaster. You see, in some areas of the United States, traffic lights are vertical, with the red light being at the top and the green light being at the bottom. For those with color deficiency, these lights are easier to read because you're looking at not just color, but position of the light. In some states, like Texas, the traffic lights are horizontal, with the lights being in a straight line, with the green on the right and the red on the left. Now imagine you are a colorblind person who's been driving for decades in an area with up and down vertical lights, where you can only tell if you need to stop at a light by position of the lights. What happens when a colorblind individual goes from vertical lights to horizontal lights without knowing it? Speaking from personal experience as a passenger in the rental car, a lot of screaming. Basically, the world is not built around color deficient individuals. Like amazing evolving creatures, these folks learn to adapt. Other interesting facts about colorblindness and color deficiency. We know that certain types of colorblindness are tied to genetics. They are passed down through maternal DNA. For a lot of men, having colorblindness came from the genes of their mother. The percentage of colorblind males in a given population rises significantly the whiter the skin of the population. Let me explain. On the continent of Africa, colorblind percentages are very small and in some countries nearly non-existent. However, in places like Scandinavia, where the population is predominantly white, the amount of colorblind men can spike to over 10%. So that 8% average that we talked about at the beginning of the episode is just that, an average for the entire world. The concentration of colorblindness depends on where you live. And finally, if you think you or a sibling or a child might be colorblind, there are some clues to look out for. Is the person constantly using the wrong color when painting or drawing an object? For example, they use purple on leaves or green on faces, and they think that those are the proper colors, having a low attention span when coloring, or denying that they have any problems with color. Another part of colorblindness can be needing to smell your food before you eat it. This is because food is less appetizing when it doesn't have bright colors. Some children with colorblindness can complain that their eyes or head hurt if they're looking at something on a red or green background. And finally, the superpower of those with colorblindness, they are very good at seeing through camouflage. Now, here's the thing about color vision deficiency. As a species, humans can only see so much on the spectrum of light. We know that there are other species of animals that can see more colors or different colors than we can see. We know that birds can see UV light, and with that I've wonder sometimes do birds look at us and call us UV light deficient? Do they look at us and go, silly humans, you can't see anything? I've always wondered that. Anyhow, I'm Mimi Fotz, and this has been another episode of Hello from the Van.