diplopii

Diplopii is a rarely used plural form that appears in some medical texts to denote multiple instances of diplopia, or double vision. In contemporary clinical language, diplopia is generally treated as an uncountable condition, and the pluralization diplopii is uncommon except in historical or linguistic discussions. The term derives from Greek roots meaning “double vision.”

Diplopia is the perception of two images of a single object. It can be monocular, persisting when one eye is closed, or binocular, occurring only when both eyes are open. Monocular diplopia usually points to anterior segment or lens problems; binocular diplopia results from misalignment of the eyes, known as strabismus or cranial nerve palsies.

Common causes include refractive error, cataract, corneal irregularities, and neurological conditions affecting eye movements, such as cranial nerve palsies, brainstem or cortical disorders, or increased intracranial pressure. Drugs or intoxication, fatigue, and certain systemic diseases can also contribute. Sudden or acute diplopia, especially with other neurologic signs, requires urgent medical evaluation to exclude dangerous etiologies.

Diagnosis relies on history, ocular motility testing, cover tests, refraction, and imaging when indicated. Treatment targets the underlying cause; options may include prism correction, patching, corrective lenses, lubrication for monocular diplopia, or surgical alignment for persistent binocular diplopia. Because diplopia can reflect serious disease, clinicians emphasize prompt assessment when onset is abrupt, new, or associated with headache, weakness, or facial numbness.