20 popular optical illusions that will blow your mind

Optical illusions have been bending our brains for centuries, delighting and confusing viewers in equal measure. Coming in many different forms, these mind-blowing popular optical illusions are a fascinating demonstration of how easily our brains can be fooled by a simple shift in colour, light or surroundings. From shape-shifting still images to mind-boggling illustrations, these viral illusions have astounded millions of viewers across the globe.

We've curated a list of our favourite popular optical illusions, covering a broad range of types, from physiological to cognitive. Among our top picks are some classics that you may have come across before, as well as a selection of the latest mind-bending visuals we've seen recently. If you're inspired by this mesmerising selection, you can create your own op-art using Photoshop or even make one from scratch with the help of our art supplies for painting guide.

Must-see optical illusions

01. Hermann grid illusion

Kicking off our list is this classic optical illusion reported back in 1870 by Ludimar Hermann. When you cast your eyes across the image you should see faint black dots between the squares that disappear when you try to focus on them.

These ghostly spots are actually a result of retinal ganglion cells that act as the output pathway of the retina. Supposedly the intersections of Hermann's grid appear dark because they produce less visual stimulation when compared to the lines. Who knew a simple grid pattern would be too complex for our brains to comprehend?

02. Super Mario optical illusion

Sometimes the best optical illusions take us by surprise, and this mind-bending Mario illusion has certainly ruffled some feathers online. If you're an optical illusion fan you might be familiar with the staircase illusion where it's difficult to tell which direction the object is heading. Place your bets, is Mario ascending or descending? The internet can't seem to decide.

Luckily we have video evidence that reveals the answer. The confusing still is taken from an animated series called the Super Mario Bros Super Show that aired back in 1999. Drum roll...he's going up the stairs. Skip to 13:33 to see for yourself.

03. Horse optical illusion

When optical illusions come to life it's always a feast for the eyes and this mesmerising horse illusion is one of our favourite examples. If you're familiar with these visual spectacles then you may have seen the walking horse optical illusion that went viral after it stumped the internet. Consider this the IRL version.

This optical illusion features a horse walking in a snowy field, sounds simple right? But the more you focus, the less clear it becomes. It sparked debate online after viewers couldn't decide which direction the horse was walking. Here's a hint – the answers in the tail. Yep, after much speculation it was confirmed that it's walking away.

04. Parallax effect optical illusion

This IRL optical illusion manages to look like a 3D render and a web design effect all at the same time, making it the ultimate illusion for creative types.

The aeroplane looks like it is hovering in midair thanks to the way the camera is panning around it, and the angle it is shooting from. An object moving at a different speed to the background is called the parallax effect (look at these parallax scrolling websites for its application in web design). Of course, the plane is just moving normally - but it gave me a shock when I saw it!

Filmed by TikTok user @abc7la aka William Mandis, it has been shared widely.

05. The expanding black hole optical illusion

Optical illusions are always pretty mind-blowing, but not many come close to this one that can show you the future - well almost. Viewers who stare into the centre of the black hole will instantly begin to see it expanding towards them, but in fact, the image is not moving at all. In actuality, it's just the viewer's brain firing back what it thinks is happening and predicting what we'll see. According to a report in the Frontiers in Human Neuroscience journal, over 86% of people who look at the illusion see the shape expanding. Are you one of them?

06. The hypnotic circle optical illusion

Created by Brusspup, the first optical illusion in our list is a bit of a geometric trick. The white circles appear to form a circular shape that rolls around the inside of the circumference of the red circle. But of course, this is an optical illusion so that couldn't actually be the case. The white circles are actually all moving in a straight lines, the timing just happens to create the illusion that they're moving in a circle. See the full video if you don't believe us!

07. The spinning vortex optical illusion

One type of optical illusion that we can't get enough of are those that appear to be moving but they're actually still images. These are examples of what are known as physiological optical illusions – they're caused by the over stimulation of the brain’s senses as a result fo the eye seeing too much colour, light, movement or dimensions to be able to process.

With its purple and yellow vortex-like design, this one's hypnotic, but we promise it's not a gif or a video. It's a completely still image. What happens is that the combination of the different patterns, light and levels tricks your mind into thinking it's moving when you let your eyes wander over the design. Concentrate on the very centre of the image and you should be able to see it stop.

08. The rotating horse optical illusion

The rotating horse optical illusion has us all asking, which way is it turning? The geometric equine kind of looks as though it snakes around, and many users on TikTok have theorised about the direction of the horse, but we still have no idea which way it turns.

09. Van Gogh Starry Night optical illusion

We're seeing stars with this trippy Van Gogh optical illusion. By staring at the rotating image above, the famous illustration will come to life in a flurry of swirls and movement. It's a great example of how our brains will twist an image based on how our eyes adjust to what they're seeing, and I could stare it for hours. Considering the original painter was a well-known addict to anise-flavoured spirit absinthe, maybe this is exactly how he envisioned the original painting.

10. How many horses are there?

Another equine-themed illusion, this one has been confusing viewers since the 1970s. The design begs the question, how many horses are in the painting? And despite how many times we counted the horses, we never got the answer that the artist, Bev Doolittle, revealed as correct. This is an optical illusion of a different kind. It's what's known as a literal optical illusion since it was created intentionally by the artist to hide or disguise things in plain view, without relying on our minds to trick us. We love them all the same.

11. The cat on the stairs optical illusion

This feline-themed optical illusion has divided the internet. It seems as though no one can decide whether the cat is walking up or down the stairs in this post. While the illusion has been doing the rounds online since 2015, we're still none the wiser about the direction of the cat. See our pick of the best animal optical illusions for more animal-oriented treats.

12. The hidden tiger optical illusion

From small cats to big cats. This is another clever illustrated optical illusion from an artist. Can you spot the hidden tiger in the picture? No, not the first tiger you see, the one that's showing us its teeth. The hidden tiger. We promise it's there lurking there in the image, and you'll kick yourself when you see it. This one is also a literal optical illusion, but one with an amusing cognitive element that made us smile.

13. The impossible slide optical illusion

Impossible Gravity Slide Illusion [Secret Revealed!] - YouTube

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If you're a really big fan of optical illusions, how about one that you can 3D print? That's exactly what Struck Duck did with this mindbender. In this optical illusion, a ball that appears to roll UP the 3D printed slide, defying gravity. But if you watch the full video, you'll see the illusion depends on the angle that you view it at.

14. The Phantom Queen optical illusion

This mind-boggling video features the 2021 winner of the Illusion of the Year contest. The Phantom Queen optical illusion sees the reflection of an invisible queen piece on a chessboard. The video pans round to reveal a clever 3D shape that aligns with the pattern of the chessboard. Hidden under that shape is the Queen, making it look as though she wasn't even on the board.

15. Moving pictures 

This mystical moving optical illusion was created by artist Akiyoshi Kitaoka. The design uses the 'anomalous motion phenomenon' to make it look as though it's moving when in reality its a totally static image. Our brain tricks us into thinking the photo is moving because of how the image hits our retinas at a particular location.

16. What's hiding amongst the stripes?

Next up on our list of optical illusions is this eye-crossing striped affair, shared by Dr Michelle Dickinson on Twitter. It springs into life when you shake your head vigorously from side to side (carefully!). An image will start to appear amongst the lines. Which type of furry friend do you see appearing?

17. Spinning discs optical illusion

This is an illusion, featured in Clive Gifford's book Eye Benders, and inspired by experimental psychologist Akiyoshi Kitaoka. No, like the first optical illusion we saw in our list, this is not a GIF but a still image – though the wheels appear to turn in front of your eyes. This happens because of how your eyes process an image, scanning it repeatedly while autofocusing and adjusting. Like in the previous example, there's a way to make it stop – try focusing on one single wheel.

18. How many numbers optical illusion

This number-themed illusion had the internet utterly stumped as it asked the question, how many numbers for you see? At first glance, it looks as though there are only three numbers, but the closer and harder you stare, the more numbers start to appear. There are seven numbers in total, but what numbers are they exactly?

19. Floating ship optical illusion

Most optical illusions seem to be handmade or digital creations, but every now and again an example appears out in the wild – and these incredible 'floating' ships might just be the most mind-boggling phenomenon we've seen. A walker was stunned to see a boat hovering above the water in Cornwall, and a photo of his discovery quickly went viral. This is one of what is a whole sub-genre of optical illusions – accidental optical illusions.

20. The union flag optical illusion

Observing the world in all its colourful glory is something many of us take for granted. But how different do things look if you're colour blind? In a video created by the BBC back in 1985, an optical illusion featuring the Union flag was created to educate people on how colour blindness works.

Viewers are asked to stare at the dot for 20 seconds, after which the screen goes white and, due to a "three receptor phenomena" the flag will appear in its original red, white and blue colours. This, as the narrator explains, is due to said phenomena forcing other colour receptors to take over when some "start to tire". Despite the illusion first being shown over 35 years old, it's still completely mind-boggling. Still celebrating Jubilee Day? Make sure you also see the Queen Elizabeth II optical illusion!

In this mesmerising video, TikTok user @alexisdiannee paints a stunning piece of op-art right before our eyes. A masterful recreation of the classic checkerboard illusion, Alexis' time-lapse is a mind-bending insight into how the simplest details can create the most striking illusions.

As Alexis adds more dotted details, the canvas warps in front of our very eyes, appearing to undulate and shift. The addition of simple white and black dots in the corner of each square tricks the brain into perceiving light and dark shadows on the flat image. If you'd like to try your hand at creating your own piece, Alexis has shared a handy tutorial that uncovers the magic behind her trippy artwork.

@alexisdiannee

♬ original sound - Lex