Date of Award


Degree Type


Degree Name

Master of Science in Vision Science

Committee Chair

Robert L. Yolton


Background: A systematic approach to determining drug intoxication has been developed for use by police officers. By considering specific physiological signs, trained officers can detect the effects of seven major drug types.

Methods: Officers follow a 12 step testing sequence and evaluate signs such as pupil sizes and responses, eye movements, heart rate, body temperature, mental timing, and balance. A matrix is then used to compare the subject's signs to those that would be produced by the seven types of drugs. If a pattern match is found, the officer concludes that the subject is under the influence of a drug and specifies the drug type.

Results: Several field and laboratory validation studies have been conducted using these procedures. In general, officers were 70 to 90% accurate in determining intoxication status and drug classification, but poly-drug use and drug rebound effects can sometimes cause problems.

Summary: Ocular and other physiological signs can be used to detect drug intoxication and classify the type of drug taken. Knowledge of the procedures used in the Drug Recognition Program can enable optometrists to serve as consultants to the police and as expert witnesses in cases involving the use of ocular signs that indicate drug use.

Included in

Optometry Commons