Guy uses a Ziploc bag to show why some things look backwards in mirrors while others don't
We get it now!

Why is text reversed in mirrors?
Have you ever wondered why text shows up backwards in a mirror? It's confusing to our brains because it doesn't seem like anything else is flipped like that. If we turn our head, it doesn't move the opposite direction in a mirror. Or does it? After all, right-handed you is actually left-handed you in the mirror. Right? (Wait, is that right?)
Mirrors can be confusing, despite not being very complicated. A mirror image is simply a reflection of what's before it. But when someone else is looking at us head on, they don't see text in reverse, so why don't we see what other people see when we see ourselves in a mirror?

(If you think this is a super stupid question with a super obvious answer, congratulations. Pat yourself on the back and scootch along so the folks who don't fully grasp the physics of mirrors can enjoy a demonstration that makes it a little easier to understand.)
"Why do mirrors reverse text?" asks the creator behind @humanteneleven on YouTube. "You might think it's just a property of mirrors—they flip things from left to right—but that's not true." He then picks up a metal arrow to show that it points the same direction in the mirror as it does in real life. So why is the text flipped when the arrow isn't?
- YouTube youtu.be
He then holds up a book to show how the text on the book cover appears backwards, just like the shirt. But when he holds up a Ziploc bag with the word "HELLO" written on it, the word shows up properly.
That's because he had to flip the book over to see the cover text in the mirror. The baggy he could just hold up and see the letters through the transparent plastic, just as we see them in real life. If he flips the baggy over like he did the book, the text shows up backwards in the mirror, just like it does in real life.
"So it's actually not the mirror that's flipping anything from left to right," he says. "It's the human."
People appreciated the simple, straightforward explanation and demonstrations.
"One of the most insightful demonstrations I've seen. It's simple and explains the phenomenon. Well done!"
"While I've heard this explanation many times before, I've only recently seen it demonstrated with text-on-transparency, which is what really makes it click. Great video!"
"Love these sorts of demonstrations. It’s a bit of a complicated one, but I love seeing how different people's minds work when explaining simple things like this. My kid explains it with “left is on the left, right is on the right, things aren’t flipped, they are mirrored” but it’s true that you are the one who flips things and I’ve never thought of it that way before."
"Oh my God, I haven't understood explanations from physics videos about why mirrors flip but this, gosh this helps."
Mirrors have been hilariously befuddling people in other videos as they try to figure out how the mirror knows what's behind a barrier placed in front of objects.
@sarahcoome this is kinda creepy 👀 #mirror #relatable #creepy
Is this something all of us should probably have learned in high school? Yes. Do all of us remember everything we learned in high school? No. Does the scientific explanation make perfect sense to everyone even if it's explained in detail? Um, no.
Like the reversed text question, having a simplified explanation that doesn't fully get into the nitty gritty physics and geometry of how mirrors work is helpful for some folks.
- YouTube youtu.be
For those who do want a bit more scientific substance to their explanations, this next video does a good job of giving a bit more detail while still keeping the explanation simple. It even uses a visual diagram to explain:
- YouTube youtu.be
And for those who say, "This is so basic! How do people not understand this?" here's a video that really does get into the nitty gritty physics and geometry of how mirrors work, diving into ray and wave optics, photons, wave functions, probability, and quantum mechanics. It's only 12 minutes, and it manages to entertain while explaining, but it certainly blows the notion that understanding mirrors is super simple.
- YouTube youtu.be
As one commenter wrote, "I thought I understood mirrors. I understand mirrors even less now. And that's a compliment."
Isn't science fun?
This article originally appeared in May. It has been updated.



A Generation Jones teenager poses in her room.Image via Wikmedia Commons
An office kitchen.via
An angry man eating spaghetti.via 



An Irish woman went to the doctor for a routine eye exam. She left with bright neon green eyes.
It's not easy seeing green.
Did she get superpowers?
Going to the eye doctor can be a hassle and a pain. It's not just the routine issues and inconveniences that come along when making a doctor appointment, but sometimes the various devices being used to check your eyes' health feel invasive and uncomfortable. But at least at the end of the appointment, most of us don't look like we're turning into The Incredible Hulk. That wasn't the case for one Irish woman.
Photographer Margerita B. Wargola was just going in for a routine eye exam at the hospital but ended up leaving with her eyes a shocking, bright neon green.
At the doctor's office, the nurse practitioner was prepping Wargola for a test with a machine that Wargola had experienced before. Before the test started, Wargola presumed the nurse had dropped some saline into her eyes, as they were feeling dry. After she blinked, everything went yellow.
Wargola and the nurse initially panicked. Neither knew what was going on as Wargola suddenly had yellow vision and radioactive-looking green eyes. After the initial shock, both realized the issue: the nurse forgot to ask Wargola to remove her contact lenses before putting contrast drops in her eyes for the exam. Wargola and the nurse quickly removed the lenses from her eyes and washed them thoroughly with saline. Fortunately, Wargola's eyes were unharmed. Unfortunately, her contacts were permanently stained and she didn't bring a spare pair.
- YouTube youtube.com
Since she has poor vision, Wargola was forced to drive herself home after the eye exam wearing the neon-green contact lenses that make her look like a member of the Green Lantern Corps. She couldn't help but laugh at her predicament and recorded a video explaining it all on social media. Since then, her video has sparked a couple Reddit threads and collected a bunch of comments on Instagram:
“But the REAL question is: do you now have X-Ray vision?”
“You can just say you're a superhero.”
“I would make a few stops on the way home just to freak some people out!”
“I would have lived it up! Grab a coffee, do grocery shopping, walk around a shopping center.”
“This one would pair well with that girl who ate something with turmeric with her invisalign on and walked around Paris smiling at people with seemingly BRIGHT YELLOW TEETH.”
“I would save those for fancy special occasions! WOW!”
“Every time I'd stop I'd turn slowly and stare at the person in the car next to me.”
“Keep them. Tell people what to do. They’ll do your bidding.”
In a follow-up Instagram video, Wargola showed her followers that she was safe at home with normal eyes, showing that the damaged contact lenses were so stained that they turned the saline solution in her contacts case into a bright Gatorade yellow. She wasn't mad at the nurse and, in fact, plans on keeping the lenses to wear on St. Patrick's Day or some other special occasion.
While no harm was done and a good laugh was had, it's still best for doctors, nurses, and patients alike to double-check and ask or tell if contact lenses are being worn before each eye test. If not, there might be more than ultra-green eyes to worry about.