Incredible optical illusion tricks your brain into seeing a green Christmas tree – here’s how it works
From the ‘Moon Illusion’ to ‘The Dress’, many mind-boggling optical illusions have been discovered over the years.
This festive illusion might be one of the most confusing yet.
This visual trick has been shared across social media and features a magically appearing Christmas tree.
During the intense illusion, the viewer’s brain is tricked into seeing a bright green tree.
In reality, however, the image remains black and white, while your brain provides all the color.
In a TikTok video, radio host Dean Jackson explains shared this astonishing illusion to the surprise of social media.
One shocked commenter wrote: ‘I saw a green tree with colored bulbs. I replayed it to make sure the ending was truly black and white. AMAZING!!!’
What colors can you see?
This mind-blowing optical illusion causes your brain to see a green Christmas tree, even though the image is black and white
For the illusion to work, you must first look closely at the colored image.
In the video, Mr Jackson says: ‘Look at this photo, stare at the red cross in the middle. Concentrate intensely on it and try to block out everything else.
“In a few seconds, I’m going to erase the photo and replace it with a black and white photo, and I hope your brain will fill in the missing colors.”
If you keep your eyes on the cross as the color fades, you should see the impression of a green tree with colored decorations and presents.
Many social media users flocked to the comments to share their experiences with the illusion.
One commenter wrote, “The red turned blue, the green turned magenta, the pink turned green, the blue turned orange, but the star turned yellow instead of orange.”
“Very clever, I saw a green tree and decorations,” another added.
While one commenter wrote: ‘The colors turned pastel!! The tree turned green, the star is yellow and the ornaments were pink.”
Staring at the pink tree first tires out the receptors in your eyes that detect magenta. When the color is removed, it leaves an inverted green afterimage
This is called the afterimage illusion and causes your brain to produce a negative version of an image you just saw. If you look at the photo of a woman on the left for seconds and then look at the white space, you should see a correctly colored image due to this effect
While the image on the screen is actually black and white, your brain is tricked into seeing the colors due to an effect called the afterimage illusion.
Just as looking at bright light leaves spots in your vision, looking at any color can cause you to see afterimages.
When you see a bright color, the light-sensitive cells in your eyes, called photoreceptors, become overstimulated and tired, causing them to lose their sensitivity.
Normally you do not notice this effect, because your eyes continuously make small movements that prevent the photoreceptors from becoming overstimulated.
However, by staring intently at the red cross, you prevent those movements from happening, so that an afterimage can arise.
The reason you see a green tree is due to something called the “opponent process theory” of color perception.
This theory claims that your vision is controlled by two systems: one that detects magenta and green, and another that detects blue and yellow.
Within each system, the two colors balance each other, so you see a normal mixture of shades.
According to the ‘opponent process theory’, our brains produce color by balancing between competing sets of light receptors. Since green is the opposite of magenta, as our magenta-sensing cells tire, the green cells overpower them, creating a green afterimage (stock image)
Scientists have discovered that optical illusions can also cause afterimages. If you stare at the white dot on the left, you should see that the space between the red corners fills in the gaps to make a complete square. If you look at the white dot on the right, that illusion also appears as an afterimage
But when one group of receptors is fatigued, the other group overcompensates and produces an inverted afterimage.
Since magenta normally balances with green, the bright magenta tree creates a green afterimage.
However, some scientists now believe that the afterimage illusion may be much more complex than once thought.
In 2001, researchers at the California Institute of Technology in Pasadena created the strange discovery that optical illusions can also create afterimages.
They found that the brain would continue to see colors created by a well-known illusion called “perceptual color filling.”
But since there is no color, the viewer’s retina cannot be fatigued.
This suggests that afterimages may be formed by adjustments in the brain itself, rather than in the eyes.
WHAT IS THE DELBOEUF ILLUSION?
The Delboeuf illusion is a type of visual illusion in which a dot surrounded by a large ring is typically perceived as smaller than a dot of the same size surrounded by a small ring.
This optical trick works because your brain perceives the dot in the context of the outer ring.
It is named after the Belgian philosopher and mathematician Joseph Remi Leopold Delboeuf (1831 – 1896), who created it in 1865.
The Delboeuf illusion is a type of visual illusion in which a dot surrounded by a large ring is typically perceived as smaller than a dot of the same size surrounded by a small ring.
When it comes to plate size, the theory is that having a smaller plate makes people think they have more food.
However, new research shows that when people are hungry, they can accurately identify the food portion, regardless of how it is served.
According to the researchers, this indicates that hunger stimulates stronger analytical processing, which is not so easily misled by the illusion.
However, it is widely believed that the Delboeuf illusion works in other contexts.