Why are ghosts bad liars?
Why this joke works
Transparently Unconvincing
Seeing right through someone means recognizing dishonesty or hidden motives. Ghosts are also traditionally transparent, allowing a person to see through them in the literal sense. Ask the setup like a question about poor acting or an obvious tell. Give the punchline cleanly and let “see right through them” carry both meanings without adding another explanation. Traditional ghost stories often portray ghosts as transparent or partly visible, providing the literal image behind the expression.
A closer look
Transparency Becomes a Failure of Deception
“See right through” someone means recognizing a dishonest motive or false story. Ghosts are commonly imagined as transparent, so the phrase also describes literal vision passing through their bodies. The question asks about lying ability rather than appearance, delaying the supernatural trait until the answer. The exclamation gives the accusation energy, while the visual image remains harmless and familiar enough for an all-ages riddle.
Fact behind the joke
Human Vision Depends on Light Reaching the Eyes
The National Eye Institute explains that light reflects from objects, enters through the cornea and pupil, and is focused onto the retina, where photoreceptors begin converting it into neural signals. Transparent materials transmit much of the light rather than scattering or absorbing it. Fictional ghosts are often drawn translucent for visual storytelling, but science has no verified optical anatomy for supernatural beings.