Doppelbildern

Doppelbildern, literally “double images” in German, is a symptom in which a single object is perceived as two separate images. In medical terminology this is called diplopia. The sensation can affect one eye (monocular diplopia) or both eyes (binocular diplopia) and can be temporary or persistent.

Monocular diplopia remains when the other eye is closed and is usually due to optical problems such as refractive error, corneal irregularities, or cataract. Binocular diplopia disappears when either eye is closed and results from misalignment of the eyes caused by muscle or nerve disorders, or by brain injuries.

Common causes include cranial nerve palsies affecting the oculomotor (III), trochlear (IV), or abducens (VI) nerves, thyroid eye disease, myasthenia gravis, orbital trauma, or vascular events such as stroke. Other causes include refractive or accommodation errors, diplopia from corneal or lens defects, and, in rare cases, brain tumors.

Diagnosis rests on clinical evaluation: history of onset and associated symptoms, visual acuity, refraction, and dedicated eye movement tests such as the cover test. Neuroimaging (MRI or CT) and blood tests may be used to identify systemic causes or brain lesions. Urgent evaluation is needed if diplopia is sudden in onset with headache, weakness, numbness, or other neurological signs.

Treatment targets the underlying cause. Optical measures such as changes in glasses or prisms can relieve diplopia in some cases. Monocular diplopia is typically corrected with lenses or surgery for cataracts or corneal problems. Binocular diplopia may require eye-muscle surgery, prism therapy, or treatment of conditions such as myasthenia gravis, thyroid eye disease, or vascular disease.

Prognosis varies with the cause; some forms resolve with treatment, while others require long-term management or adaptation. An accurate diagnosis is essential because sudden or new diplopia may indicate potentially serious conditions, including stroke or brain tumors.