Crusty and red eyes: what to know

Crust forms when tears, mucus or discharge dries on the lashes. Redness means the small blood vessels on the eye surface are more visible. Irritation from smoke, dust, dry air, cosmetics or rubbing can cause both. Itching and watery discharge fit an allergic pattern, while thicker sticky discharge and eyelids that cling together can occur with conjunctivitis.

These features overlap, so crust colour alone cannot tell you which cause is present. Notice whether one eye or both are affected, whether the problem began after a cold or exposure, and whether there is pain, blurred vision or sensitivity to light.

Wash your hands, then place a clean lukewarm compress over closed lids to soften the crust. Wipe gently from the inner corner outward with a fresh pad, and do not share towels, pillows or eye cosmetics. Avoid rubbing, picking at the crust or putting non-prescribed products into the eye.

Remove contact lenses and discard any eye makeup used while the eye was symptomatic. A pharmacist or clinician can advise on suitable lubricating or allergy treatment. Antibiotic drops are not appropriate for every red eye and should not be borrowed or saved from a previous illness.

Seek urgent assessment for severe pain, reduced or distorted vision, intense light sensitivity, an eye injury, chemical splash, marked swelling, or a red painful eye in a contact lens wearer. Emergency help is also needed if a child seems very unwell or cannot open the eye.

Book a review if redness or crusting persists, repeatedly returns, spreads to the other eye, or is not improving with gentle care. Avoid driving if discharge or blurred vision affects sight.

Ask whether the findings fit Conjunctivitis or allergic conjunctivitis and whether testing is needed. Tell the clinician when the crust started, its texture, any itching or pain, contact lens use, recent respiratory illness, new products near the eyes and any change in vision.