Illinois State Police
Study of Pupillometry used in Law Enforcement

In 1996, the Illinois State Police (ISP) began measuring pupillary response with the EyeCheck™ instrument. The EyeCheck™ instrument was developed by MCJ, Inc. Rockford, Illinois. MCJ Inc. is a research and development company which investigates non-invasive technologies for determining impairment with biometrics. EyeCheck™ is a non-invasive instrument, which introduces a light stimulus to a subject's pupil, and measure the subsequent pupillary reaction or pupillary dynamic. Pupillary movement provides indications of activity within the body's central nervous system. Interpretation of pupillary reaction has assisted in determining possible impairment caused by alcohol, drugs, or fatigue.

On July 1, 2000, Public Act 91-881 was passed and amended 625ILCS 5/11/-501/5 by adding paragraph (b) to the section. The added paragraph states, "The Department of the State Police shall create a pilot program to establish the effectiveness of the pupillometer technology…" The bill mandated an 18-month pilot program utilizing 15 instruments. The purpose of the project was to determine if pupillometer technology could detect motor vehicle drivers' impairment caused by alcohol and or drugs. In addition, the amendment specified the measurement of fatigue levels in commercial motor vehicle drivers. A training curriculum was developed by the ISP Academy staff and MCJ Inc. to accomplish the mandate set by Public Act 91-881.

The pilot involved collecting data for 18-months and on November 15, 2001, data was forwarded to the New England College of Optometry for analysis. Upon analysis, it was concluded Pupillometry can be used as an objective measure to screen and identify reduced alertness as a result of sleepiness or fatigue. It was also determined pupillometry can be used to screen and identify subjects potentially under the influence of drugs.

Pupillometry has proven, through empirical testing, to be an effective tool which can assist in the detection, confirmation, and ultimate prosecution of impaired drivers. Impairment not involving alcohol can be difficult to identify and even more difficult to confirm and prove. The use of the pupillometer as a screening instrument would aid in identifying impairment and expedite roadside evaluation of a suspected impaired driver.