Why reading or using phones during a car ride makes people feel sick

Reading or scrolling through a phone during a car ride triggers motion sickness due to a mismatch between sensory signals received by the brain. The eyes focus on a stationary object like a book or mobile phone, while the inner ear senses that the body is in motion. This conflict between visual and vestibular information triggers symptoms including nausea, dizziness, sweating, headache, and sometimes vomiting.

Causes and Risk Factors

The inner ear contains specialised structures that detect changes in movement, direction, and acceleration. When a person travels in a car, these structures continuously send movement-related signals to the brain. Fixing the eyes on a reading page creates the false impression of a stationary environment. Individual susceptibility varies based on age, genetics, migraine history, and sensory conflict sensitivity. Children between two and twelve years old are especially prone to this condition, along with individuals who suffer from migraines.

Symptoms and Prevention

Symptom severity increases when a vehicle frequently accelerates, brakes, or changes direction, or when sitting in the back seat where the road ahead is less visible. Poor ventilation, strong odours, anxiety, fatigue, and dehydration also worsen the condition. The simplest preventive step is to avoid reading or using a phone while moving. Instead, looking outside at the horizon or distant stable objects helps the brain reconcile visual information with inner ear movement. Sitting in the front passenger seat, keeping the head still, ensuring fresh air, and taking breaks during long trips also help.

Context

Motion sickness is a very common physical reaction to perceived movement that does not match visual input. While usually harmless, persistent symptoms outside of travel require medical attention to rule out other health issues.