It’s the year 2050. You’re sprinting through the dark, futuristic streets of New York City. Above you is the distant hum of the robotic overlords scanning for any signs of life.
. But the machines can’t detect you. Why?
Because you’ve become invisible. Sounds like something straight out of sci-fi, right? But here’s the wild part—this isn’t fiction.
Believe it or not, this jaw-dropping ability all started back in 2024… with a bag of Doritos. Yep, you heard that right! Scientists have just made a ground-breaking discovery that brings us one step closer to turning invisible.
So how did they pull this off? And what does it mean for the future of humankind? On today’s episode of The Infographics Show, we’ll uncover how scientists have cracked the code to make skin transparent.
To figure out how we can make skin invisible, first we have to discover why it looks solid. Imagine if you could see right through your skin—veins, bones, everything. Thankfully, that’s not how our bodies work.
Without this natural filter, every look in the mirror would be like something from a horror movie—a creepy thought, right? But what makes our skin this perfect shield? It’s a bit of science magic called the refractive index— basically, how much a material like your skin bends light.
When light hits your skin, it scatters in all directions, that’s why you can’t see through it. Skin is made up of different materials packed together - fat, fluid, protein, and other structures. Each has a different refractive index, so the light scatters in all directions and doesn’t get through.
Now, there are a few exceptions to this rule, as you might notice if you glance down at the top of your hand and spot some veins popping up. For a lot of people, veins will show up where the skin is thinnest - hands, wrists, ribs, breasts, and the top of the feet. Some people have translucent skin, which isn’t fully see-through, but it does allow you to see a lot more veins, and in rare cases, even tendons inside the skin.
Usually, it’s caused by very, very pale or thin skin, which can happen in albinos or those with vitiligo. People who become very thin and lose the fat under their skin can also have veins pop up. Many seek treatment for translucent skin.
But lately, a group of scientists decided to go against the grain and try to make skin even more translucent. Meaning, completely invisible. They started by looking at how skin blocks light and trying to reverse the process.
They would have to find a way to make all materials inside the skin bend light in the exact same way and at the same speed. In other words, give every material the same refractive index. How could they even begin to do this?
Well, the answer lay in something shockingly simple… Food dye. Thanks to decades of research in optics, scientists already knew that colored food dyes were good at absorbing light. That's how they give artificial food its color.
It’s why your Fruit Roll-Ups have a color you won’t find in anything grown outside a lab- which means they’re definitely not a sign of something healthy. This absorption also means dyes can direct light through any material much faster by changing the way it scatters. Zihao Ou, a postdoctoral researcher at Stanford University at the time, decided to find the substance that would make skin invisible once and for all.
His team of scientists landed on the yellow food dye found in products like candy corn, tortilla chips, and Doritos, called tartrazine. While no nutritionist would recommend putting these things in your body, Ou saw it differently. The research partners knew tartrazine, better known as FD&C Yellow No.
5, absorbed most kinds of light, including blue and ultraviolet light, which often hit skin. That’s why it shows up as the opposite color on the color wheel - a mix of orange and yellow. To test out his hypothesis, he started by using sliced chicken breasts.
Even if something went wrong, the worst that could happen is one less order of chicken nuggets in the world. Ou and Hong mixed tartrazine with water, rubbed it on the chicken breasts…and to their amazement, the chicken turned transparent to red light. Now, it was time to try the experiment on a living thing.
So they turned to scientists' favorite subjects…mice. Apparently no humans signed up to risk becoming permanently invisible. The researchers shaved the hair off the mice, then they took their food dye and water solution, and rubbed it onto the bald and very confused animals’ skin.
The dye absorbed most of the light hitting it. This made the refractive index of the watery skin tissue the same as the index of the surrounding proteins and fats. The result was jaw-dropping.
Scientists could now see through the mice’s skin, and get a glimpse of their organs and blood…without opening them up! This included blood vessels on the surface of the brain, and organs in the stomach area. The report from the study said the researchers could even watch the mice digest in real time.
The mice’s inner body looked a little orange - yellow, thanks to the food dye used, but everything was still visible It just had the same filter Hollywood uses when filming a scene set in the Middle East. The crazy thing is that an author had thought of this solution 127 years before scientists ever came up with it! H.
G. Wells wrote “The Invisible Man” in 1897, back when leeches were still an important part of medicine. His main character invents a serum to make his body invisible.
It works because it makes his body’s refractive index match up with the index of the air around him. Either Wells was psychic, or scientists had better things on their to-do list than turning skin invisible. But most people aren’t really curious about what a particular mouse ate that day.
Cartoons have told us it’s probably just cheese stolen from a mouse trap. So how does this breakthrough help? Turns out, in lots of ways.
Making skin invisible will help with diagnoses, surgeries, and procedures. One common issue that this technique can address is finding veins. In many people - especially the elderly - it’s challenging to find veins needed for blood draws and injections.
Jabbing around results in pain, bruises, and small burst veins, not to mention angry patients. Scientists also believe creating invisible skin will help locate skin cancer earlier. The affected areas will stand out among the invisible skin.
Light traveling further into the skin can also help with deep tissue treatments, as you can see the tissue you are treating. Better yet, doctors being able to see inside patients without opening them up can help identify problems without surgery. Getting anesthesia and having your organs exposed to the air is always a risk; invisible skin can lessen the amount of times that needs to happen.
And good news for anyone who still has an “I love Mia” tattoo dedicated to the girl who dumped them five years ago: Yellow No. 5 will make laser tattoo removal much faster and easier. Speaking of changes to the body, invisible skin will open up a whole new world.
In the future, besides tattoos and piercings, visible veins might become a new trend. When a mom yells at her kid to stop walking around with their stomach showing, she might be talking about their actual stomach. At the end of the day, it wouldn’t be a big deal thanks to one of the biggest advantages of using food dye.
It only takes a few minutes to show up and make the skin invisible. After you wash the skin, it returns to normal without any terrible side effects - so far, at least. Other treatments scientists tried caused skin swelling and other permanent changes.
But there are still a few steps researchers have to take before all these techniques are developed. The first and most important step is testing tartrazine on humans. Scientists are optimistic, but they will have to change some things.
For starters, they will have to adjust the dose, as human skin is ten times thicker than the skin of a mouse. Human skin is also built differently, as the line between the epidermis - outer skin - and dermis - inner skin - is flat in mice, but wavelike in humans. This could cause potential problems.
The other problem is that Yellow No. 5 can’t turn bones invisible. And humans have a whole lot of them.
So the view into the human body will be blocked in many places. But at least areas around the body’s core, which holds many important organs, will be visible no matter what. But even if and after Yellow No.
5 is safely tested on humans, can it become a mass market medical solution? Ou seems to think so. The dye is safe for people, and according to him, “very inexpensive and efficient; we don’t need very much of it to work.
” Yet, the food dye has drawn negative attention from some scientists and state governments. A 2022 study by the California Office of Environmental Health Hazard Assessment said that Yellow No. 5 caused behavioral problems in children, and made them less able to pay attention.
California has already introduced a bill that would ban this food dye in public school meals if it becomes a law. That being said, if the dye can help with much more serious medical issues, this probably wouldn’t stop its use in healthcare. Not to mention that having the dye rubbed on your skin causes very different effects than eating the dye.
After all, no one has turned invisible after eating nachos - yet. Ou is excited to continue testing Yellow No. 5, eventually using it on humans, while also figuring out if there is anything that could make bones transparent as well.
He points out a lot of exciting possibilities for the future. “A partially transparent mouse will already enable numerous research opportunities to answer questions relating to development, regeneration, as well as aging”, the last of which will get the studies major funding from Hollywood. Now go check out Scientist Reveal How A Zombie Apocalypse Could Really Happen or click this video instead.
