Provided are systems and methods for detecting blood alcohol level. The system for detecting blood alcohol level comprises a receiver configurable to receive an input video of an eye of a user and a processor configurable to: stabilize the input video analyze the input video based on the analysis, detect a horizontal gaze nystagmus level and based on the horizontal gaze nystagmus level, determine an equivalent blood alcohol level of the user. The system outputs data associated with the equivalent blood alcohol level via an interface. Additionally, the system comprises a screen configurable to display a moving object. The input video captures eye movements of the user following the moving object. To illuminate the eye of the user, the system may generate red light.
