It's All in the Eyes
By Wanda Laukkanen
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A police car with red and blue flashing lights pulls over a suspected drunk driver. The driver steps out and the policeman asks him to use his eyes to follow his forefinger as it moves back and forth, up and down.
A simple test, but one that may have grave consequences should the driver "flunk" it. Called the horizontal gaze nystagmus test, the procedure, which has undergone rigorous testing by the Pacific University College of Optometry and elsewhere, is one of three standardized field sobriety tests used often by police officers who suspect impairment of drivers via alcohol and/or drugs.
If done correctly, the simple test provides officers with the evidence they need to further test a motorist's alcohol level or let him go, says Dr. Karl Citek, professor of optometry at Pacific's College of Optometry and one of the leading experts on the horizontal gaze nystagmus test.
What the test does is allow a properly trained officer to gauge the extent of abnormal eye movements should the driver be impaired. Basically, consumption of alcohol causes involuntary jerky eye movements as a person tries to follow an object with his eyes, says Citek. The involuntary movements are noticeable to the properly trained person regardless of whether the subject is standing, sitting or even lying down, he says. If a person is impaired, officers can see "a very consistent pattern of abnormal movements of the eye," he says. The test, along with other field sobriety tests, also is used in educational and occupational settings as a non-invasive assessment of impairment of students and workers, respectively.
An alcohol-impaired person can't make the compensatory movements he needs to correct the jerky motion of his eyes. That's why driving drunk "makes it so dangerous," Citek notes. The alcohol affects the brain and its visual function in a way that is completely involuntary.
Research by the college also indicates that other conditions, such as sleep deprivation, do not cause the kind of jerky eye movements that alcohol consumption does, Citek notes.
Citek become involved in the horizontal gaze nystagmus test in 1995 when he first came to Pacific to work and met Dr. Robert Yolton, a now retired professor of optometry who is also one of experts in this field.
The test is in use by police officers around the county. Along with Yolton, Citek became involved with training law enforcement personnel about the test. They have developed a four-hour program for drug recognition experts in Oregon and Washington that teaches the hows and why of the test. That program has also been condensed to an hour and half format for other law enforcement personnel, prosecutors and other legal experts on alcohol and drug impairment. In addition, the training program has been expanded to a three-day adjunct course at University of North Florida for law enforcement personnel and prosecutors, says Citek.
Law enforcement people really appreciate the training, he notes. "They're so appreciative and so understanding. It makes sense to them," he says.
In addition to providing training to law enforcement, Citek has traveled around the northern hemisphere providing testimony at legal hearings about the eye test, going to places as varied as Honolulu to the Virgin Islands to Montana, Kansas and a variety of other states. The horizontal gaze nystagmus test is also something that is taught to optometry students at Pacific as part of basic anatomy and physiology courses in the college.
Karl Citek has been a professor of optometry at Pacific since 1996. He earned a doctor of optometry degree from State University of New York in 1993. He also holds a Ph.D. in vision science from the same institution