You've clearly been living under a rock, if you haven't encountered "The Dress" — that is, the viral image that some people perceived as white and gold, while others saw it as blue and black. It caused quite a bit of head-scratching on social media, especially when it was finally revealed that it was actually blue and black. I know... I don't get it either.

Since then, we have seen plenty more optical illusions that have perplexed the people of the internet. From disappearing dots to some very shiny legs, here are 13 of the most mind-twisting illusions we've seen recently.

1. The bridge to nowhere

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The Storseisundet Bridge in Norway makes for such a dramatic illusion that it has actually been known to make motorists turn their car around.

The cantilever bridge — which is part of the Atlanterhavsveien (Atlantic Road) — is built in such a manner that from a certain angle it looks more like a diving board than a bridge. As you approach, it appears as if the bridge abruptly ends, making drivers fear that they will plunge into the waters below.

It's appropriately dubbed The Drunk Bridge, although it's perfectly safe with a maximum clearance to the sea of 75 ft.

2. The Dress

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'The Dress' caused quite the social media craze back in 2015. Twitter users were close to tearing their hair out over the image, which people either perceive as being black and blue or white and gold.

Well, 'The Dress' is, in fact, black and blue, but the reason why the majority of people saw it as white and gold (me included) is due to something called "colour constancy".

The term refers to the idea that the context or surroundings in which we see an object influences our perception of what colour it is. So, per Slate, the reason why people see "The Dress" differently is due to a difference in opinion in regards to whether the viewer believes that the photo was taken inside or outside. Natural daylight tends to have a blue tinge, while artificial indoor lighting has more of a yellow hue.

3. The red strawberries

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An image shared to Twitter by Japanese Professor of Psychology, Akiyoshi Kitaoka — who specialises in creating optical illusions, and sharing them online — shows a bunch of strawberries on a tart, with a blue filter added on top.

While we see the strawberries as red, there's actually not a single red pixel in the image. As Kitaoka explains: "Illusion of strawberry by the two-colour method. Although this image are [sic] all made of the pixels of the cyan (blue-green), strawberries appear red. Strawberries appear to be reddish, though the pixels are not."

Basically, we're so used to perceiving strawberries as red that we automatically see them like that.

4. Floating speaker

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Now, this is one uncanny photo.

Although the speaker appears to be floating in mid-air, it's only the shadow of the flag that creates the illusion.

What do you see?

5. Duck or rabbit?

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Ever heard of thee Gestalt Shift?

A good example of this is Wittgenstein's duck-rabbit illusion. Here, you can either see the duck or the rabbit, but never both at the same time.

It's not about which animal you see first, but about how quickly your mind is able to switch between seeing the duck and the rabbit.

6. The greyscale retailer

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While out shopping in Asda, YouTuber Holly McKee found a real-life optical illusion, which made her think she'd temporarily gone colour-blind.

As she was walking through the children's clothing area, she came across an aisle of black and white clothes, which made it look like a filter had been applied to the image.

But after people on Twitter accused her of editing the photo, she made a video to prove that it was real.

7. Neck or back

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This illusion seriously confused Twitter — while it looks like we're looking at someone's neck, it is, in fact, their back.

I know, weird, right?

What do you see?

8. The shoe

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Very similar to the infamous 'The Dress', 'The Shoe' nearly broke the Internet again.

Some perceived it to be green and grey, while others saw it as pink and white. As you've probably guessed, colour constancy is to blame once again.

9. The wooden train track

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A parent quickly went viral on Twitter when he shared a video of his child's wooden train tracks.

One track block is longer than the other, but when he put it on top of the other, they were the same length.

This phenomenon is known as the Jastrow Illusion, and you'll likely see it if you're around children's toys for an extended period of time.

10. Disappearing dots

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This image is a real brain teaser.

Actually, there are 12 dots in the image, but your brain won't let you see them all at once — simply as it's very difficult to focus on them all at the same time.

It's doable, but expect a headache afterwards...

11. Shiny legs or paint?

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Sure, it looks like there's a layer of gloss on this woman's legs.

But really it's just splatters of white paint.

Bizarre!

12. The owl

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On first glance, you may have thought you saw an owl, right?

Actually, what you're looking at is a mug of coffee two with two Cheerio cereal pieces floating on the top.

Take another look and let us know what you see.

13. The mountain man

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Sometimes an "optical illusion" is just a perfectly cast shadow — as is the case here.

In the picture above, it looks like a man is superimposed onto a mountain-scape.

However, it's really just the shadow.

13 optical illusions that have been tearing the Internet apart