In today’s optical illusion challenge, test your eyesight with a tricky number puzzle. Hidden among 3s and 4s is a single number 8—only those with sharp vision can spot it. This fun eye test evaluates ...

Moiré illusions can be visually captivating ... Nominally, the motors spin relatively slowly, generating a pleasing, hypnotic effect when turning the discs. The drivetrain is under the control ...