Q: Why did the officer make me follow a penlight with my eyes to the left and right?
The officer asked you to follow a penlight with your eyes to the left and right as part of a field sobriety test. This particular test, known as the Horizontal Gaze Nystagmus (HGN) test, is often used by law enforcement to determine if a driver may be under the influence of alcohol or drugs. The test assesses the movement of your eyes as you track the light. Officers look for specific signs, such as the inability of your eyes to smoothly follow the light or the presence of distinct jerking motions, which can indicate impairment.
During the HGN test, the officer will typically observe for three criteria: the angle at which the jerking of the eyes begins, the inability to smoothly follow the light, and whether the jerking occurs at a 45-degree angle. These observations help the officer form an assessment regarding your level of impairment. It is important to note that the results of this test are subjective, and factors other than alcohol or drugs, such as medical conditions or fatigue, can affect the outcome.
In California, the HGN test is one of several field sobriety tests that an officer may employ during a DUI investigation. If you believe that the process was not conducted properly or if the test results were misrepresented, it may be beneficial to speak with a legal professional who specializes in DUI cases to better understand your rights and options.