There is a wide-range of standardized field sobriety tests (SFSTs), including heel-to-toe, finger-to-nose, one-leg stand, "horizontal gaze nystagmus" test, alphabet recitation, modified position of attention (Rhomberg), fingers-to-thumb, hand pat and others. In Rhode Island, most officers will use a set battery of three common tests - the heel-to-toe, one-leg stand, and the horizontal gaze nystagmus test.
Unlike the chemical test, where refusal to submit may have serious consequences, Rhode Island DUI law does not require you to take any of the Standardized Field Sobriety Tests (SFSTs). The reality is that officers have usually made up their minds to make a DUI arrest when they give the SFSTs; the tests are simply additional evidence which the suspect inevitably "fails." Thus, in most cases a polite refusal may be appropriate and smart.
This is the "horizontal gaze nystagmus" test, a relatively recent development in DUI investigation. The officer attempts to estimate the angle at which the eye begins to jerk ("nystagmus" is medical jargon for a distinctive eye oscillation). If this occurs sooner than 45 degrees, it theoretically indicates a blood-alcohol concentration over .08%. The smoothness of the eyes tracking the penlight (or finger or pencil) is also a factor, as is the type of jerking when the eye is as far to the side as it can go.
This field sobriety test has proven to be subject to a number of different problems, not the least of which is the non-medically trained officer's ability to recognize nystagmus and estimate the angle of onset. Because of this, and the fact that the test is not accepted by the medical community, it is not admissible as evidence in many states and Attorney Friel has been very successful in excluding this evidence in court.