Red eyes often accompany a cold, and there’s a direct link between these two. The same viruses causing a cold can affect the eyes. Understanding this connection helps distinguish cold-related red eyes from other potential causes.
The Cold-Red Eye Connection
A common cold, a viral upper respiratory infection, can lead to red eyes through direct and indirect mechanisms. Cold viruses, like adenoviruses, can directly infect the conjunctiva, the clear membrane covering the eye’s white part and inner eyelids. This infection causes viral conjunctivitis, often called “pink eye,” characterized by redness, watery discharge, and irritation. It frequently starts in one eye and may spread to the other.
Indirectly, congested sinuses from a cold can put pressure around the eyes, causing redness and discomfort. The general discomfort, irritation, or fatigue accompanying a cold can also lead to increased eye rubbing. Rubbing eyes can cause tiny blood vessels on the surface to break or dilate, leading to visible redness. The body’s overall inflammatory response to a viral infection also contributes to localized redness in the eyes, as blood vessels expand to facilitate the immune response.
Distinguishing Red Eyes
Red eyes can stem from various causes beyond a common cold. Allergic reactions, for instance, often cause red, itchy, and watery eyes, typically affecting both eyes simultaneously. These symptoms usually accompany sneezing and nasal congestion, but generally lack typical cold symptoms like a sore throat or body aches.
Bacterial conjunctivitis is another cause of red eyes. It often features a thick, pus-like discharge that can be yellow or green, and may cause eyelids to stick together, especially upon waking. This infection often requires medical treatment. Dry eye syndrome, resulting from insufficient tear production or poor tear quality, can lead to chronic redness, a gritty sensation, and burning. Symptoms can be worsened by prolonged screen time or environmental factors.
Eye strain, often from extended screen use or reading, can cause temporary redness and fatigue that resolves with rest. Environmental irritants like smoke, dust, chemicals, or strong fumes can also temporarily irritate and redden the eyes.
When to Consult a Doctor
While red eyes during a cold are often not serious, certain warning signs indicate a need for professional medical attention. Consult a doctor if you experience persistent or worsening redness, severe eye pain, or extreme sensitivity to light. Any vision changes, such as blurring, decreased vision, or loss of vision, warrant immediate medical evaluation.
Thick, yellow, or green discharge from the eye is also a reason to seek medical advice, as this may suggest a bacterial infection. If redness does not improve within a few days, even as cold symptoms resolve, or if accompanied by other systemic symptoms like fever, chills, or a headache, consult a doctor. Contact lens wearers should remove lenses immediately if redness or discomfort occurs and seek prompt medical advice, due to a higher risk of serious eye infections.