Short answer
Most conjunctivitis clears up and does not harm vision. The type matters because the treatment differs: thick yellow pus points to bacteria, watery tearing with a cold points to a virus, intense itching in both eyes points to allergy. Contact lenses come out straight away. But if there is severe pain, light sensitivity or loss of vision, this is no longer an ordinary pink eye and the eye needs to be looked at the same day.
Have you ever woken up with a gritty, uncomfortable sensation in your eye, noticed in the mirror that the white part of your eye turned pink or bright red, or found your eyelids stuck together with discharge? Red eye and eye inflammation are among the most common reasons patients seek ophthalmic care.
While people often refer to any eye redness simply as eye inflammation, medically it covers distinct conditions. The most frequent cause of a red eye is conjunctivitis, commonly known as pink eye. The conjunctiva is a thin, transparent membrane that covers the white surface of the eyeball, the sclera, and lines the inside of the eyelids. When small blood vessels in this membrane become inflamed or dilated, the eye appears visibly red.
Primary types of conjunctivitis and their causes
Conjunctivitis is grouped into four main categories by cause. Identifying the right type matters, because the wrong medication — antibiotics for an allergy, for instance — brings no relief and can irritate the eye further.
Bacterial conjunctivitis · staphylococci, streptococci, pneumococci
Signs. Red eye, gritty discomfort, eyelids and lashes glued together overnight.
Discharge. Thick, yellow or greenish pus.
Contagious. High
First-line care. Prescription antibiotic drops or ointment — fusidic acid, tobramycin, ciprofloxacin. Symptoms usually settle in 3 to 5 days. Finish the course even once the eye looks well.
Viral conjunctivitis · most often adenoviruses
Signs. Redness, burning, swollen lids, often with a cold. Tender lymph nodes near the ear.
Discharge. Watery and clear.
Contagious. Very high
First-line care. There is usually no specific antiviral drop. Cold compresses, preservative-free artificial tears, strict hygiene. It resolves on its own in 1 to 3 weeks.
Allergic conjunctivitis · pollen, dust mites, pet dander, cosmetics
Signs. Intense itching. Both eyes redden at once, lids swell, often with allergic rhinitis.
Discharge. Watery or slightly mucous.
Contagious. Not contagious
First-line care. Antihistamine eye drops, mast cell stabilisers, allergen avoidance. Cool artificial tears help rinse allergens off the surface.
Irritant and contact-lens inflammation · chlorine, smoke, dust, dry eye, overwear
Signs. Redness, dryness, a foreign-body sensation.
Discharge. Minimal and watery.
Contagious. Not contagious
First-line care. The first step is taking the lenses out and letting the eye heal. The next question is whether lenses are needed at all.
Contact lenses reduce corneal oxygenation. Sleeping in lenses, poor hygiene or overwear creates chronic micro-irritation, which is favourable ground for dangerous bacteria such as Pseudomonas aeruginosa.
Red eye symptoms and red flags
While typical conjunctivitis resolves without vision loss, a red eye can indicate serious, sight-threatening conditions such as keratitis, a corneal infection, uveitis, intraocular inflammation, or acute glaucoma.
Ordinary, harmless symptoms. Mild to moderate redness. Watery or sticky discharge. A gritty or sandpaper sensation. Slight lid swelling.
Red flags: seek ophthalmic care the same day
- Severe or worsening eye pain. Ordinary conjunctivitis causes discomfort; sharp, aching pain points to corneal or intraocular inflammation.
- Photophobia. If looking at bright light causes sharp pain, it may be corneal damage or uveitis.
- Reduced or blurry vision. If acuity drops noticeably and does not clear on blinking or wiping discharge away.
- Unequal pupils or a cloudy cornea. If one pupil is noticeably larger or smaller than the other, or the cornea looks dull and matt.
- A red eye in a contact lens wearer. Remove the lens at once and have the eye examined to rule out a corneal ulcer.
Diagnosis and treatment options
The right treatment depends on an exact diagnosis, made by an ophthalmologist or optometrist at the slit lamp. Treatment follows the cause.
- BacterialPrescription antibiotic eye drops or ointments: fusidic acid, tobramycin, ciprofloxacin. Symptoms usually settle within 3 to 5 days, and the course is finished even once the eye looks well.
- ViralSupportive care: cold compresses, preservative-free lubricating drops and strict hygiene. It resolves in 1 to 3 weeks.
- AllergicAntihistamine eye drops, mast cell stabilisers and allergen avoidance. Cool artificial tears help rinse allergens off the surface.
A warning on home remedies
Do not wash an inflamed eye with tea bags or herbal infusions. Tea particles and non-sterile liquids can scratch the cornea and worsen the infection. Use only sterile saline or lubricating drops.
Preventing spread and recurrence
- Wash your hands often, with soap and warm water, before and after touching your eyes.
- Do not rub your eyes. Rubbing carries bacteria straight from your hands into an irritated eye and can damage the cornea.
- Use your own towel. Do not share towels, pillowcases or face-care products.
- Throw away contaminated make-up. Mascara, eyeliner and eyeshadow used during the infection go in the bin to avoid re-infection.
- Leave the lenses out while you are unwell. Wear glasses until the eye has fully healed.
Contact lenses and chronic irritation
Long-term daily contact lens wear is one of the most common causes of chronic ocular irritation, redness and recurrent conjunctivitis. The lens acts as a foreign body on the eye, interrupting the natural spread of the tear film and limiting corneal oxygenation.
One distinct form is giant papillary conjunctivitis, or GPC, where the inner surfaces of the eyelids become irritated and inflamed from contact lenses constantly rubbing against them. It can appear at any time, even after many years of trouble-free lens wear. GPC does not harm vision, but it is persistent.
When lenses keep irritating the eye
The first step is taking the lenses out and letting the eye heal. The second question is whether lenses are needed at all. Take the lens off the eye and the lens-induced irritation goes with it — the tear film and corneal oxygenation work as they are meant to.
KSA's Flow3 laser procedure corrects vision in the surface layers of the cornea, without cuts or flaps. Flow3 is for people aged 18 to 45 whose myopia has been confirmed at the suitability examination — whether it suits your eye is decided at the Audit eye examination, not by the name of the procedure.
If the irritation is driven by dry eye rather than by the lenses, that has its own treatment path and dropping the lenses alone will not settle it.
When to come to KSA
If the eye is red and any red flag is present — severe pain, light sensitivity, loss of vision, unequal pupils, or you wear contact lenses — do not wait. We see patients in Tallinn and Tartu.
If the eye is settled but the redness keeps returning, it is worth finding the cause: recurrent conjunctivitis is usually driven by lens wear, allergy or dry eye. That is what the Audit eye examination works through.
Closely related: dry eye, myopia and astigmatism.