Ocular behavior measures were measured with a prototype device, the Fitness Impairment Tester (FIT), following ingestion of four different drugs: codeine (a narcotic-analgesic), alprazolam (a CNS depressant), d-amphetamine (a CNS stimulant), and cannabis. The FIT provides 100 measures of ocular performance that are derived from tests requiring saccadic eye movements in response to a `jumping' target, smooth tracking movements in response to smoothly moving target, steady fixations (vs nystagmus) in response to targets appearing in the peripheral field, pupil dilation and constriction in response to changes in background luminance, and convergence of the two eyes in response to a target moving towards the observer. The present study analyzed the data obtained from a sample of self-proclaimed drug users after administrations of placebo, low, and high dosage levels of the four different drugs, and compared their performance to non-dosed normal subjects. The sensitivity and specificity of the over 100 ocular measures were assessed in terms of their ability to distinguish the presence of drugs. (A)
Abstract