FIELD SOBRIETY TESTS #3
The National Highway Traffic Safety Administration recommends police administer three "Standardized Field Sobriety Tests" to assess whether individuals are under the influence of drugs or drink. Failure of all three tests has been shown to correlate highly with a blood alcohol concentration over the limit: 0.08g/1,000 millilitres.
HORIZONTAL GAZE NYSTAGMUS--Nystagmus is an involuntary jerking o fthe eyes that is exaggerated by alcohol. The suspect is asked to track a slowly moving object (such as a pen or flashlight) with each eye; police watch the angle at which ther jerking begins, the type of jerking when the eye is as far to one side as possible, and whether the eye is able to smoothly trace the object. Displaying four signs of impairment between the two eyes is highly correlated with a BAC >0.08.
Comte de Buffon (1707-88)