Why does a stye cause red eye?

A stye is a tender, localised lump that forms when a gland near an eyelash becomes blocked and inflamed. The eyelid may swell, feel sore, and look pink or red. Irritation from the swollen lid can make the white part of the eye appear bloodshot, especially close to the affected lid. Red Eye is a common presentation of Stye, but red eye can also arise from dry eye, allergy, infection, an injury, or a contact-lens problem.

A small yellow point may appear on the eyelid as the stye drains. Crusting on the lashes after sleep can occur. These features help a clinician distinguish an eyelid problem from inflammation that starts on the surface of the eye.

Place a clean warm compress over the closed eyelid for several minutes, then gently clean any discharge from the lid with clean water. Wash your hands before touching the area. Do not squeeze, pierce, or try to pop the lump, as this can worsen irritation. Pause eye makeup and contact lenses until the eye is comfortable and the lid has settled.

A pharmacist or clinician can advise on suitable pain relief and whether an examination or prescribed treatment is needed. Avoid sharing towels, face cloths, or eye cosmetics while the eye is inflamed.

Get urgent medical assessment for severe eye pain, marked light sensitivity, reduced vision, pain when moving the eye, a rapidly spreading swollen eyelid, fever, or redness that spreads across the face. Seek prompt advice if you wear contact lenses and develop a red painful eye. Arrange a review if the lump keeps returning, does not improve, or the redness is worsening.

Ask whether the redness is limited to the eyelid area or involves the eye surface, whether you should stop wearing lenses, and what changes would mean you need a same-day review.