Legal Definitions - nystagmus

Nystagmus refers to the rapid, involuntary, and repetitive jerking or twitching movements of a person's eyes. These eye movements are beyond an individual's control and can sometimes indicate impairment, such as from alcohol or drug consumption, or certain medical conditions.

• Example 1: Field Sobriety Test

  During a traffic stop, a police officer suspects a driver of being under the influence of alcohol. As part of the field sobriety tests, the officer asks the driver to follow a pen with their eyes without moving their head. The officer observes the driver's eyes exhibiting distinct, involuntary jerking movements as they attempt to track the pen.

  This observation of nystagmus provides the officer with probable cause to suspect the driver is impaired, as it is a common indicator of alcohol or drug influence.

• Example 2: Workplace Safety Investigation

  After a minor industrial accident, a company supervisor interviews an employee involved. While speaking with the employee, the supervisor notices that the employee's eyes appear to dart back and forth uncontrollably, even when trying to focus. This raises immediate concerns about the employee's fitness for duty.

  The involuntary eye movements (nystagmus) prompt the supervisor to initiate the company's protocol for suspected impairment, potentially leading to a drug test and an investigation into whether the employee violated workplace safety policies.

• Example 3: Medical Evaluation for a Legal Claim

  A plaintiff in a personal injury lawsuit claims to have sustained a traumatic brain injury after a fall. As part of the expert medical evaluation for the lawsuit, a neurologist examines the plaintiff. During the examination, the neurologist performs specific eye movement tests and objectively notes the presence of nystagmus, indicating a disruption in the plaintiff's neurological function.

  The neurologist's finding of nystagmus serves as objective medical evidence supporting the plaintiff's claim of neurological damage resulting from the fall, which can be presented in court to demonstrate the extent and validity of their injuries.