What effect do narcotics have on the pupils of the eye?

What effect do narcotics have on the pupils of the eye?

• A. Pupil dilation
• B. Pupil constriction
• C. No change in the pupils
• D. Pupils enlarge in darkness

Answer: (B)

Narcotics cause constricted pupils, a condition called miosis. Opioids stimulate receptors in the brain that boost parasympathetic signals to the eye, making the iris sphincter muscle contract and shrink the pupil. Clinically this appears as tiny, “pinpoint” pupils that react slowly to light. In contrast, pupil dilation happens with sympathetic stimulation or certain other drugs, and darkness would normally cause dilation, not constriction, so the narcotics’ effect to constrict the pupil is the correct and distinctive sign.

Narcotics cause constricted pupils, a condition called miosis. Opioids stimulate receptors in the brain that boost parasympathetic signals to the eye, making the iris sphincter muscle contract and shrink the pupil. Clinically this appears as tiny, “pinpoint” pupils that react slowly to light. In contrast, pupil dilation happens with sympathetic stimulation or certain other drugs, and darkness would normally cause dilation, not constriction, so the narcotics’ effect to constrict the pupil is the correct and distinctive sign.