The Track Pants Optical Illusion meme features a photo of a woman wearing black track pants with a bold white stripe down the side, which creates a striking visual glitch. At first glance, the white stripe looks like the gap between two impossibly thin legs rather than a pattern on the fabric, leading many viewers to do a double-take. It first gained viral traction on social media platforms like Twitter and Reddit around 2018, as users debated what they were actually seeing. Since then, the template has been used to represent situations where the truth is hidden in plain sight or to describe any scenario that is inherently confusing and requires a second look to truly understand.