With 2008's The Dark Knight, Heath Ledger gave us one of the all-time defining Joker portrayals, which was
There's no arguing that the Joker stabbing a pencil into a table and then forcing someone's head onto the writing instrument with so much force that it disappears would be incredibly painful, yet Nerdist revealed the specifics of how the victim could have recuperated.
The video claims that the bones behind the eye are about as thin as a playing card, positing that the eye was the most likely entry point for the pencil. Other parts of the skull are so thick that it would be more likely for a pencil to shatter than to be forced through the bone.
Based on the standard sized pencil, there would also be enough room in the skull to accommodate the object, proving that it was at least physically possible for a pencil to completely disappear inside someone's head.
While none of us want any objects to enter our head, a pencil is only one of many objects that medical science has documented puncturing the brain. Chopsticks, toothbrushes
Rather than the injury itself being the most dangerous element of a pencil getting embedded into your eye, the original risks with the wound came from infection. Injuries of this nature that were recorded as early as the 1800s resulted in a near 100% mortality rate, yet as treatments for the injury evolved, that rate steadily declined over the years.
Not only do victims of this type of injury recover, they often regain complete neurological functions.
For the henchman in The Dark Knight to have died, he most likely would have had to have been neglected completely and never receive any medical attention.
[H/T YouTube, Nerdist]