THIS mind-boggling illusion used to demonstrate what people with colourblindness can see has blown the minds of social media users.
All you have to do is stare at the middle of the green, yellow, and black version of the Union Jack flag.
This will then disappear and you may see the traditional red, white, and blue flag.
The video was made in 1985 for the BBC but has since resurfaced after being posted online by BBC Archive.
Stare at the dot in the centre of the flag and then when the screen goes blank, you may see the right colours of the flag.
One social media user wrote on X: “Brilliant. It definitely works, I was able to see the Union flag!”
“That Union Jack trick still freaks me out to this day!” another said.
“I saw the Union Jack in its true colours. Unbelievable!” a third added.
After carrying out the trick, the narrator explained how it works.
It's all down to the three receptor theory about the human retina which contains three types of colour receptors known as cone cells which each have different absorption spectra – red, green, and blue.
So, when looking at the green part of the illusion, it is the green and blue cones that get fatigued and fail to respond properly when the white screen flashes up.
But the red cones that were not used in the illusion were not fatigued and so worked normally meaning you see red when the blank screen pops up.
At the same time, the yellow parts of the illusion activate and tire out your red and green cones leaving just the blue working normally which then turns what was yellow, blue, when you look at a blank screen.
This is similar to what colourblind people experience as the may lack cones sensitive to one of these three colours meaning they end up seeing a different colour.
The narrator explained: “We can never know the actual colours they experience, but can get an idea of the range of sensations because we know which colours look identical to them”.
There are four different kinds of colour blindness with the condition affecting one in 12 men and one in 200 women.
How can optical illusions and brainteasers help me?
Engaging in activities like solving optical illusions and brainteasers can have many cognitive benefits as it can stimulate various brain regions.
Some benefits include:
- Cognitive stimulation: Engaging in these activities challenges the brain, promoting mental agility and flexibility.
- Problem-solving skills: Regular practice enhances analytical thinking and problem-solving abilities.
- Memory improvement:These challenges often require memory recall and can contribute to better memory function.
- Creativity:They encourage thinking outside the box, fostering creativity and innovative thought processes.
- Focus and attention:Working on optical illusions and brainteasers requires concentration, contributing to improved focus.
- Stress relief:The enjoyable nature of these puzzles can act as a form of relaxation and stress relief.
But optical illusions are not only good for testing your ability to see colour.
They can also be used to reveal your true personality traits.
There are also numerous cognitive benefits to putting your brain through its paces with illusions and puzzles.
So you might want to try Flying Eze'swide range mind-boggling challengescreated to stimulate the deepest parts of your brain.
In this mind-bending image, everyone can count the ducks but if you can find the hidden needle among the reeds in less than seven seconds, you may have 20/20 vision.
Another tricky brainteaser features a gnarled tree but only those with high IQ can spot a sleepy cathiding on it.
Have a go at the puzzles below and when you are ready, scroll down to see the answer.
