One A and a lot of Fs. This is the illustration that has gone viral as the newest optical illusion. It comes with a challenge and the user has to find the letter A hidden in a sea of Fs. It seems easy enough but many users have struggled with it. They want to complete it and the timer and demonstrate their focus and skill.
The Rise of Viral Brain Teasers
In the last few years online visual puzzles and optical illusions have become popular. Puzzles that target people’s observation skills have become increasingly popular. This new illusion is inline with the growing trend and offers a challenge in which users have to find the letter A in under 10 seconds.
A Puzzle Rooted in Psychology

The increasing popularity of the such puzzles is proof of how the human brain works and processes information, in this case how the brain perceives visually. It is easy for the human eyes to overlook something important in a patterned and repetitive visual. The challenge is compounded by the fact that the letter A and the letter F contain similar components: the lines are angled and when there are a lot of Fs it is overwhelming.
Internet Users Take Up the Challenge
Social media users have begun to take the challenge and find the letter A. They show their result and how long it took to find the letter across social media such as X (Twitter), Instagram, and Facebook. A multitude of people gleefully recall the moment they found the elusive ‘A’ while others, more contritely, admit that the task took longer than it ought to have. This social aspect of the task has driven up interest, as friends try to outdo one another to see who has the most accurate vision.
Not Just Fun, But Training for the Mind
This may seem to be a task of little importance but researchers suggest that completing such tasks is beneficial to increasing one’s level of focus and mental speed. Spot the difference puzzles help the brain to work more efficiently when looking for differences, therefore serving a dual purpose as a source of entertainment and a mental exercise.
Where to Find the Challenge
The image at the centre of this viral quiz consists of the rows and columns of the letter F. Within the grid, an ‘A’ is situated and ready to be found. The image and the challenge is being shared across the internet by puzzle sites and Ascii art communities who encourage people to challenge themselves and try to finish the task in ten seconds.
Optical illusion Answer

The internet remains fascinated and engaged with concealed images, such as hidden animals in complex landscapes, or disguised shapes in a block of text. The challenge of the ‘A’ among the ‘F’’s is the latest illustration of how an unexpected optical illusion can evolve into a worldwide race, proving that the internet still enjoys a good test of endurance and discrimination.