Physicians Dr. Lewis Fisher and Dr. Isaac H. Jones published an article “Vertigo and Seasickness, Their Relation to the Ear” in the New York Medical Journal in 1916, claiming that the condition was related to “a disturbance in the ear.” That is why “Persons in whom the mechanism has been destroyed — deaf-mutes, for instance — never suffer from mal de mer.”

Their hypothesis basically still holds up today. WebMD says, “You get motion sickness when one part of your balance-sensing system (your inner ear , eyes, and sensory nerves) senses that your body is moving, but the other parts don’t. For example, if you are in the cabin of a moving ship, your inner ear may sense the motion of waves, but your eyes don’t see any movement.”

Cause of Seasickness Discovered at Last?: Ailment Is a Form of Vertigo and Results from a Disturbance in the Ear, According to Two Physicians Who Have Made Tests

From October 29, 1916