A Field Sobriety Test is a series of physical and cognitive assessments conducted by law enforcement officers to determine if a driver is impaired, often due to alcohol or drugs. These tests typically include tasks like walking in a straight line, balancing on one leg, and following a moving object with the eyes. The results of these tests help officers decide whether to arrest a driver for suspected driving under the influence (DUI). While these tests are designed to be simple, various factors, such as medical conditions or environmental distractions, can affect a person's performance.