Optical illusions are mind-bending pictures that have gained popularity among netizens during the last decade.
These challenges put your vision and visual skills to the test, allowing scientists to better understand how the human brain processes visual information.
It is thought that optical illusions might improve cognitive ability and drive the brain to think creatively.
Regular practice with such difficulties improves memory and problem-solving skills.
A hidden letter can be found in the above highly coloured image, which appears to be abstract art.
Only the most observant readers have a chance of completing this challenge within the time restriction.
Readers who spotted the concealed letter within 6 seconds earn a round of congratulations for their keen visual abilities.
Some of you may still be scratching your heads, looking for the explanation.
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