Can a Horizontal Gaze Nystagmus Test be Admitted in a DUI Trial?

A Nystagmus test is a FST given roadside to a supected DUI driver, the test looks for a jerking of the eyeball while it tracks a pen the officer is holding.  Before the officer may testify to the Horizontal Gaze Nystagmus test results, prosecution must produce expert testimony that the test is widely accepted for determining blood alcohol concentrations.  This expert cannot be an officer or a crime lab technician according to the california case of People v. Kelly (1976) 17 Cal. 3d 24 and a single expert will not be sufficient, as the Supreme Court said in Kelly, it is “Questionable whether the testimony of a single witness alone is ever sufficient to represent, or attest to, the views of an entire scientific community.” People v. Kelly, supra at p.37. Furthermore, the prosecution must prove that the test was correctly administered to the defendant. In People v. Williams, (1992, 5th  Dist.)  3 Cal. App.4th 1326, the arresting officer was permitted at trial to testify that in his opinion, based partly on the Nystagmus test, the defendant was under the influence of alcohol.  This was permitted by the trial court after the officer testified he had received 10-hours of classroom instruction on Nystagmus at the CHP Academy, 8-hours of laboratory time, and had given the test in the field about 250 times.  The trial court ruled that this was insufficient evidence to qualify the officer as an expert