Ingenious optical illusion billboard takes the terror out of the prostate check

We've seen plenty of weird and wonderful optical illusions here at Creative Bloq, but here's one that hits a bum note – for all the right reasons. To celebrate Prostate Cancer Awareness Month earlier this month, charity Prost8 shared a cheeky billboard campaign with an important message.

"A prostate check isn't what you think," reads the tagline, which appears to have been slapped over a close-up photograph of a pair of buttocks. It's only when reading the tagline that it becomes clear that this is a clever anatomical illusion. (Looking for more design inspiration? Check out the best print ads of all time.)

"It's just a blood test taken from your arm," completes the tagline. At which point it becomes clear that these aren't buttocks at all, what we're looking at is a photo of an arm.

The campaign was designed by TBWA\MCR. "One man dies of prostate cancer every 45 minutes in the UK," reads the agency's case study. "If more men were tested, more would live. But testing is often avoided because of a misconception we needed to correct. Using billboards, we showed giant close-ups of where a prostate check is taken from. The arm. Despite what many people believe, a finger up the bottom is not the only way of testing prostate health. Instead, it’s often done with a simple blood test. These billboards ran across London during Prostate Cancer Awareness Month 2024."

From phenomenons that baffle even rats to brand new colours, we've seen plenty of double-take worthy examples in recent months. For our pick of the best, take a look at the best optical illusions of all time.