A sinus infection, also known as sinusitis, involves inflammation of the air-filled cavities within the bones of the skull that connect to the nasal cavity. Double vision, medically termed diplopia, is a condition where a single object appears as two distinct images. This visual disturbance can occur when both eyes are open, or sometimes even when only one eye is open.
Understanding the Connection
While a typical sinus infection does not cause double vision, a severe, untreated infection can potentially lead to this symptom. The paranasal sinuses, particularly the ethmoid and sphenoid sinuses, are located near the eyes and the nerves that control eye movement and vision.
Inflammation and swelling from a severe sinus infection can extend beyond the sinus cavities. For example, an infection can spread to the soft tissues surrounding the eye within the eye socket, a serious condition called orbital cellulitis. This infection can cause swelling that may damage the optic nerve or interfere with blood flow to parts of the eye, potentially paralyzing eye muscles and leading to misalignment and double vision.
Another severe complication is cavernous sinus thrombosis, which involves a blood clot in the cavernous sinuses, hollow spaces located under the brain, behind the eye sockets. These sinuses contain several cranial nerves responsible for eye movement. A severe infection, often originating from the paranasal sinuses, face, or teeth, can spread to the cavernous sinuses, leading to clot formation. This clot can compress or inflame these nerves, resulting in double vision, often accompanied by severe headache, eye pain, and bulging eyes.
Other Causes of Double Vision
Double vision can arise from various conditions beyond severe sinus infections, affecting the eyes, nerves, or brain. Eye-related issues commonly cause double vision in one eye (monocular diplopia). Examples include astigmatism, which is an irregularly shaped cornea, or cataracts, a clouding of the eye’s lens. Dry eye syndrome can also cause blurred or fluctuating vision.
When double vision affects both eyes (binocular diplopia) and resolves when one eye is covered, it often indicates an alignment problem between the eyes. This can stem from issues with the muscles controlling eye movement or the nerves supplying them. Neurological conditions like multiple sclerosis or myasthenia gravis, an autoimmune disease affecting nerve-muscle communication, can impair eye muscle function.
Brain-related problems, such as a stroke, brain tumor, or an aneurysm, can also disrupt the visual pathways or the cranial nerves controlling eye movement, leading to double vision. Other systemic diseases, like thyroid eye disease (Graves’ disease), can cause inflammation and swelling of the eye muscles, resulting in misalignment and double vision. Diabetes can also lead to nerve damage, affecting the cranial nerves that control eye movement.
When to Seek Medical Attention
Double vision is a symptom that always warrants a medical evaluation to determine its underlying cause. If you experience sudden onset of double vision, it is particularly important to seek prompt medical attention. This is especially true if the double vision is accompanied by other concerning symptoms.
Seek immediate care if double vision occurs with a severe headache, eye pain, fever, a bulging eye, or any changes in vision such as vision loss. Other red flags include weakness, numbness, slurred speech, or changes in consciousness. These combined symptoms could indicate a serious or life-threatening condition.