From rare genetic traits to surprising post-surgery effects, the human body is capable of some truly unusual features. Thanks to social media, people have shared personal examples that are both strange and fascinating. While some are medical anomalies and others are harmless conditions, they show just how unique and unpredictable our bodies can be.

1 A Pupil that Slowly Took Over his Iris.

At the age of 17, this Reddit user noticed that his left pupil was slowly expanding until it nearly overtook his iris. Meanwhile, his right eye has always had a mesmerizing mix of brown and blue. It’s a rare case of two different ocular anomalies in one person—and it’s absolutely striking.

2 Born Without Fingernails

This man has anonychia, a genetic condition that left him with no fingernails at all. While it might look unusual, it’s completely harmless. He doesn’t miss them either—no nail trimming, no hangnails, and certainly no nail-biting habits.

3 Skin that Writes Back

A person with dermatographia can lightly scratch their skin and leave behind raised, red marks for a few minutes. This harmless condition essentially turns skin into a temporary sketchpad, where even the faintest trace can stand out like writing on paper.

4 Incredibly Flexible Fingers

Thanks to joint hypermobility, this Reddit user can bend her fingers in ways that seem to defy the laws of anatomy. The finger joints appear to fold backward, making her hand movements look like optical illusions in real life.

5 Hair Growing on his Palm

After receiving a skin graft a few years ago, this man noticed something strange—hair began growing on the palm of his hand. It turns out the grafted skin came from a hair-bearing part of his body, and it brought the follicles along with it.

6 Spider-like Fingers from Marfan Syndrome

This user’s unusually long and slender fingers are a result of Marfan syndrome, a condition characterized by abnormalities in the connective tissue. While the condition requires careful health monitoring, one visible marker is elongated limbs and fingers that resemble spider legs.

7 A Tongue with Deep Cracks

Fissured tongue is a harmless but uncommon condition where deep grooves develop along the tongue’s surface. This user has it—and avoids pineapple, which can sting in those cracks. It may look startling, but it’s usually nothing to worry about.

8 Missing Brain Tissue, but Full of Surprises

Doctors once told this man he’d never walk or talk due to missing parts of his brain seen in his MRI. But he went on to prove them wrong, living a functional life despite the unexplained gaps that still baffle medical experts.

9 Backward Grip from Hypermobility

This man can grip objects backward, thanks to extreme hypermobility in his wrists and fingers. The motion looks completely unnatural—but for him, it’s just another way to hold a can or pick something up off the floor.

10 Eyes so Light, they Look Unreal

Megan Richmond’s eyes went viral on Instagram—and for good reason. With no colored contacts or editing tricks, her unusually pale irises make her look like a real-life fantasy character. It’s a natural genetic trait that leaves everyone stunned.