Morphine commonly causes which ocular effect?

Morphine commonly causes which ocular effect?

• A. Miosis
• B. Mydriasis
• C. Ptosis
• D. Nystagmus

Answer: (A)

Opioids like morphine commonly cause miosis, a pinching of the pupil to a small, constricted size. This happens because opioids increase parasympathetic outflow to the pupillary sphincter via mu-receptor activity, leading to pupil constriction. Clinically, pinpoint pupils are a classic sign of opioid effect or overdose. In contrast, dilation (mydriasis) occurs with sympathetic activation or anticholinergic effects, not with morphine; ptosis and nystagmus aren’t typical features of opioid-induced eye changes.

Opioids like morphine commonly cause miosis, a pinching of the pupil to a small, constricted size. This happens because opioids increase parasympathetic outflow to the pupillary sphincter via mu-receptor activity, leading to pupil constriction. Clinically, pinpoint pupils are a classic sign of opioid effect or overdose. In contrast, dilation (mydriasis) occurs with sympathetic activation or anticholinergic effects, not with morphine; ptosis and nystagmus aren’t typical features of opioid-induced eye changes.