You can't see me, but I can see you; To be more specific, I see through. What am I?

Why this works

This riddle plays on the dual meanings of "see" and "through." An X-ray is a medical imaging technique that allows doctors to "see" inside the body without invasive procedures, hence it can "see through" your skin and tissues. The twist is that while we can't see the X-ray itself (as it's a form of radiation), it is indeed capable of revealing what lies beneath the surface—making it the perfect answer!