Miosis: Is the narrowing of the

Miosis is the narrowing of the pupil, which can be normal or abnormal depending on the situation. Learn about the causes, diagnosis and treatment of miosis, and how it differs from mydriasis and pinpoint pupils. Miosis Definition Miosis is a medical term referring to the constriction of the pupil. Miosis is also known as myosis. Both terms refer to the closing of the pupil through the actions of small muscles in the eye. Miosis reduces the amount of light that enters the eye, which is necessary in daily life as the levels of light change in an organism’s environment. Miosis can also be induced by a wide variety of medicinal and recreational drugs, and is sometimes one of the diagnosing criteria ... Miosis Miosis is a medical term for constriction of the pupil. It is the opposite of mydriasis. It is seen in a variety of medical conditions, and can also be caused by certain drugs and chemicals. Eye drops used to intentionally cause miosis are known as “miotics”. Extreme miosis is commonly called “pinpoint pupils”, a situation that can be caused by use of opiates. There are two types of muscle that control the size of the iris: circular muscle and radial muscle (Figures 1 and 2 ... If your pupil is abnormally small (less than 2mm) in diameter and unresponsive to light, it’s called a pinpoint pupil. This condition is also referred to as miosis or myosis. Miosis can affect one (unilateral) or both eyes (bilateral). Miosis is not a disease but may signal an underlying problem.