Definition of mydriasis in English:


Pronunciation /mīˈdrīəsəs/ /maɪˈdraɪəsəs/


  • Dilation of the pupil of the eye.

    ‘Its strong alpha properties, especially at higher dosages, leads to mydriasis (ie, pupil dilation).’
    • ‘Long-term therapy is required, and the drugs have numerous side effects, including dry mouth, dry eyes, constipation, blurry vision, mydriasis, and difficulty with urination.’
    • ‘Often mydriasis occurs with the pupils poorly reactive or non-reactive to light.’
    • ‘Exposure could also lead to eye irritation, including conjunctivitis, mydriasis, and optic nerve damage.’
    • ‘With long-term administration, restlessness, sleeplessness, mydriasis, headaches and cardiac dysfunction can occasionally appear.’


Early 19th century via Latin from Greek mudriasis.