Double vision, or diplopia, occurs when a person sees two images of a single object. While most sinus infections cause common symptoms like facial pressure and congestion, a severe infection can rarely result in double vision. This symptom is a significant finding that suggests the infection has spread beyond the protective bony boundaries of the sinus cavities, signaling a serious, potentially life-threatening complication.
The Connection Between Sinuses and Vision
The proximity of the paranasal sinuses to the eye socket, or orbit, is the anatomical reason a sinus infection can affect vision. The ethmoid sinuses, in particular, are located directly between the eyes, separated from the orbit only by thin layers of bone. When a bacterial infection causes severe inflammation and pus accumulation within these cavities, the resulting pressure can press directly against the orbital wall. This increased pressure can displace the eyeball slightly or interfere with the function of the muscles and nerves controlling eye movement. Inflammation or compression of these nerves or muscles prevents the eyes from aligning correctly, which results in double vision.
Severe Sinus Complications Causing Double Vision
Double vision resulting from sinusitis is typically a symptom of an infection that has progressed to a condition like orbital cellulitis. This involves a bacterial infection spreading from the sinus cavity into the soft tissues and fat located within the orbit, behind the eye. The infection causes intense swelling that can physically push the eyeball forward, a condition known as proptosis. The swelling also restricts the movement of the eye muscles, leading to misalignment and the inability to move the eye fully in certain directions. Orbital cellulitis is a medical emergency because the pressure can compromise blood flow to the optic nerve, potentially causing permanent vision loss. Immediate treatment with intravenous antibiotics is required to resolve the infection and reduce the dangerous pressure on the orbital structures.
Cavernous Sinus Thrombosis
A less common but even more severe complication is cavernous sinus thrombosis, which is a blood clot forming in the cavernous sinus, a large vein located at the base of the brain. An infection from the face or sinuses can spread to this area, causing the body to form a clot in an attempt to contain the bacteria. The cavernous sinus contains the cranial nerves responsible for controlling eye movement and sensation. Damage to these nerves results in diplopia. This complication is particularly dangerous because the clot can block blood drainage from the brain and eyes, carrying a high risk of long-term damage or mortality.
When to Seek Urgent Medical Care
The onset of double vision during a sinus infection must be treated as a medical emergency requiring immediate attention at an emergency room. Diplopia suggests the infection is actively spreading to structures near or in the brain. Waiting to see if the symptom improves can lead to rapid deterioration and permanent complications, including blindness or neurological damage.
Other specific symptoms that should prompt an immediate emergency visit include:
- A severe, persistent headache that does not respond to common pain relievers.
- New or worsening swelling, redness, or bulging around the eye, especially when accompanied by a high fever.
- An inability to move the eye.
- A stiff neck.
- Confusion or altered mental status.