Factual error: Proteus refills its air supply in the lungs. The lungs are filled with normal sized oxygen molecules. How are they supposed to breathe them? (In the book, they had a miniaturizer on the sub, but there is nothing in the movie to explain this.)
Factual error: During the whole voyage except when getting very close to the heart there is no pulse seen either in the blood or acting on the vessel.
Factual error: Where is all the light coming from inside the body?
Answer: The miniaturized sub was injected into the man's carotid artery (neck) because it directly led to the brain and the blood clot. It was an unobstructed pathway taking the least amount of time for the sixty-minute mission. Exiting through the eye was done as an emergency escape route after the mission was sabotaged and the sub was destroyed. It was only easy to remove the crew once they exited the eye and were floating in the tears. Getting to and out the eye was difficult.
raywest ★