When California-based artist Concetta Antico looks up at the night sky, she doesn’t just see pitch black. Instead, the night sky transforms into brilliant blues, violets, and even green-hued colors. Antico tells us that she can even detect the glow surrounding stars. The moon is surrounded by a rainbow hue. For Antico, the night sky is alive with color.

Why does Antico observe the world in a completely different way than the rest of us? The answer lies in her genes. The artist tested positive for the tetrachromacy gene, meaning she has four cone cells in her eyes (though it’s difficult to determine if she is a tetrachromat conclusively, as the gene is not always expressed).

Why is this unusual? Well, as Reddit user griswaffle mentioned in Reddit’s Today I Learned community, most humans are trichromatic, meaning we have three cone cells in our eyes. This allows us to see reds, greens, and blues, University of Washington ophthalmologist Jay Neitz tells Upvoted.

Notice the word most? Some of us are color blind (around eight percent of men and one percent of women). Many color blind people are dichromatic, meaning they only have two cone cells, instead of the usual three. To understand how missing just one cone cell makes a dramatic difference in how you see the world, check out the photos below.

Here’s an unedited photograph. If you’re trichromat (most common in humans), you’ll see vibrant red and bold orange shirts.

Now take a look at what the same photo looks like to people with common forms of color blindness. In protanopia, people lack red cone cells. In deuteranopes, green cone cells are missing.

The world looks a bit faded, doesn’t it? Even the subtle nuances of skin color are lost. Now imagine how different that photo might look to someone who has a fourth cone.

Basically, we’re color blind in comparison to tetrachromats. In fact, the average human—a trichromat—can see about 10 million colors. But Neitz says it’s estimated that tetrachromats can see an astounding 100 million colors.

This might be why Antico doesn’t view skin as one uniform shade. “Skin color has many colors in it,” she tells Upvoted.

Antico claims that she can notice when someone is ill simply by looking them: Their skin fades to a more pale, translucent color, sometimes even transforming into a yellowish gray, if the person is Caucasian. She says she can tell when someone is flushed or feverish—because their face turns brighter.

Kimberly Jameson, a University of California, Irvine scientist who studied Antico, wrote that human tetrachromacy may be evolutionary advantageous, considering color perception has made it easier for humans to recognize disease. Doctors with normal vision can tell when someone has jaundice, for example, because of a yellowish skin color. Red indicates a rash.

In Jameson’s study, she found that laboratory assistants who tested positive for the tetrachromacy gene gave different diagnoses to patients than those without the gene.

“Color deficient doctors may miss symptoms because of an inability to perceive the color of disease,” explains Jameson.

Having a heightened sense of vision is not always beneficial, however. When Antico enters a grocery store or mall, she’s sensitive to the palette surrounding her.

“Everything is plastic and plain, and has a very flat color. There are no surprises. No mosaic of colors within colors. The colors are artificial and crass,” she says.

She describes flowers, on the other hand, as the exact opposite of a suburban mall.

“Their colors are infinite and surprising,” Antico describes. “Roses in particular offer so many colors hidden in their petals, even blues and greens and violets and yellows in what others will see as a pink rose!”

It’s clear that Antico has extraordinary vision—she passed color vision tests given to her by ophthalmologist Neitz in record time. While it’s very likely she is indeed a tetrachromat, it’s difficult to know for certain without further testing.

One thing, though, is for sure: For Antico, her heightened vision has ultimately been a blessing rather than a curse.

“I can’t imagine what it would be like not to see all the beauty in the world the way I do,” she says. “It inspires me and my art every day.”