From poking their own eyes, to drinking a patient's vomit, some extremely passionate scientists have done pretty outrageous things to themselves in the name of science.

Your brain does its best to inform you about the world around you, but sometimes it gets tricked. Enjoy eight optical illusions to test your brain’s sensory input.

From poking their own eyes, to drinking a patient's vomit, some extremely passionate scientists have done pretty outrageous things to themselves in the name of science.