A red, watering eye with discharge that glues the lashes together in the morning — and the questions arrive immediately. Is it contagious? Do I need drops? Antibiotics? See a doctor, or wait it out? Conjunctivitis (“pink eye”) is one of the most common reasons people seek help for a red eye, and also one of the conditions surrounded by the most unnecessary treatment. The plain truth: most of these infections need no medication at all — but you do need to know how to tell the types apart, and to recognise the few situations that call for urgent examination. That is exactly what this page sorts out.
What the conjunctiva is, and what happens when it is inflamed
The conjunctiva is a thin, transparent membrane covering the white of the eye and the inner surface of the eyelids. When it is irritated or infected, its tiny blood vessels dilate — and that is what turns the eye pink-red. At the same time the conjunctiva secretes more fluid, which produces the watering and the discharge. It is worth saying at the outset: conjunctivitis, however annoying, almost never threatens vision — the cornea and sight itself are not involved. Precisely for that reason, genuine pain or blurred vision are signs that something else is going on, and I come back to those below.
The three types — and how to tell them apart
Almost every case of conjunctivitis belongs to one of three types, and each has its own calling card.
Viral conjunctivitis — the most common of all. Usually caused by adenovirus, the same family of viruses behind the common cold. The discharge is watery and tearing, the eye is irritated and burning, sometimes there is a tender lymph node in front of the ear, and the classic picture is unmistakable: it starts in one eye and “jumps” to the other within two or three days. Often someone at home or at work is unwell, or you had a cold yourself. It is highly contagious — but it clears on its own.
Bacterial conjunctivitis. Here the discharge is the story: thick, purulent, yellow-green, gluing the lashes in the morning until the eye is hard to open. It is more common in children. It too, contrary to what most people assume, resolves on its own in most cases — although here antibiotic drops sometimes have a real role in shortening the course.
Allergic conjunctivitis. The guiding word is itching. Both eyes together, itchy, red and watering, usually in spring and summer or on exposure to dust and pets, and often alongside allergic rhinitis and sneezing. It is not contagious at all, and its treatment is entirely different — which is why it matters not to confuse it with the infectious types.
There are also simple irritant reactions — pool chlorine, smoke, dust, chemicals — which settle within hours to a day or two after the exposure stops.
Why most cases do not need antibiotic drops
This is the point I most want to get across, because this is where most of the unnecessary treatment happens. Viral conjunctivitis — the most common type — does not respond to antibiotics at all. Antibiotics kill bacteria; against a virus they are powerless. And yet countless viral eyes are given antibiotic drops “just to be safe” — with no benefit, with needless exposure to side effects, and with a small contribution to antibiotic resistance.
In mild bacterial conjunctivitis too, large studies show that most cases resolve within a week even without treatment. Antibiotic drops shorten the course and reduce transmission — so they do have a place, mainly when the discharge is significant — but they are not an automatic requirement for every red eye. Where is there no argument? Contact lens wearers with a red, discharging eye (more on that shortly), copious purulent discharge, newborns, and cases where the doctor has identified a specific cause that needs treating.
What does help in the meantime, across all types: preservative-free artificial tears to ease the irritation, cool compresses (particularly soothing in viral and allergic cases), gentle cleaning of the discharge with a wipe or damp cotton wool, and plenty of hand hygiene. In allergic conjunctivitis the foundation is different: dedicated anti-allergy drops, avoiding rubbing (which only amplifies the reaction) and treating the underlying allergy.
How long it stays contagious — and what to do about children
Viral conjunctivitis is highly contagious, roughly for as long as the eye is red and watering — usually one to two weeks, sometimes longer. Transmission is via hands, towels, pillowcases and anything that touches the eyes. In a household with a case: a separate towel for each person, a fresh pillowcase, handwashing after every contact with the face, and no touching the eyes. Eye makeup and contact lenses used during the infection should be thrown away.
With children the practical question is nursery: with active viral conjunctivitis (a watering, discharging eye) it is better to stay home — in a nursery, transmission is close to inevitable. With bacterial conjunctivitis the accepted approach is returning about 24 hours after treatment starts, once the discharge is settling. And one reminder for parents: a child with ongoing eye discharge for weeks, without real redness, probably does not have recurrent conjunctivitis but something else (a blocked tear duct in toddlers, for instance), and deserves a proper examination rather than another round of drops.
Discharge without inflammation? Probably the eyelids
A considerable share of people searching for “eye discharge” do not have conjunctivitis at all. Morning crusting, a mild whitish-mucous discharge, a gritty sensation — with no real redness and no acute course — often come from blepharitis, chronic inflammation of the eyelid margins, or from dry eye. These are chronic ocular surface conditions, and their treatment — eyelid hygiene, warm compresses, treating the meibomian glands — is completely different from treating a transient infection. If your “infection” has been going on for a month, it is probably not an infection.
The red flags: when this is not just conjunctivitis
Most cases can be managed at home. But there is a short list of signs where I ask people not to wait:
- Genuine eye pain — as distinct from burning, itching or discomfort. Pain is a sign of corneal involvement or deeper inflammation.
- Strong light sensitivity — another marker raising suspicion of corneal involvement or intraocular inflammation.
- Any change in vision — simple conjunctivitis blurs momentarily because of tears and discharge, but that blur clears with a blink. Persistent blur is a red flag.
- Contact lens wearers — a red, discharging eye in a lens wearer is corneal infection until proven otherwise. Remove the lens and get examined the same day; do not “wait and see”.
- Copious, rapidly progressive purulent discharge — an aggressive bacterial infection needing immediate treatment.
- Newborns in their first month — a red, discharging eye in a newborn is always examined, and urgently.
- Blisters around the eye or on the nose — suspicion of herpes, which requires specific treatment.
In every one of these situations, the difference between “another pink eye” and a significant problem comes down to a slit-lamp examination — a matter of minutes with an ophthalmologist, which immediately separates an inflamed conjunctiva from an involved cornea. Incidentally, a red eye with no discharge and no pain is a separate story altogether — I have written at length about all the causes of a red eye on the red eyes page.
What I check in the clinic
When a patient comes in with conjunctivitis, the examination is short but answers three questions: which type this is (usually clear from the history and the appearance), whether the cornea is clean and safe, and whether there is a genuine need for medication or whether it can be spared. When needed, the diagnosis can be refined with additional testing. My aim is twofold: not to miss the unusual case that requires treatment, and — no less important — not to pile treatments onto the routine case that will resolve by itself.
If your red eye comes with pain, light sensitivity or a change in vision, if you wear contact lenses, or if the inflammation simply is not settling after a week or two — you are welcome to get in touch and book an examination at my clinic in Haifa, serving patients from across northern Israel. We will examine it, know within minutes what we are dealing with, and you will leave with a clear plan — which, honestly, is sometimes simply to let the eye heal in peace.
Frequently asked questions
How can I tell whether conjunctivitis is viral or bacterial? There is no completely certain way to know at home, but there are good clues. Viral conjunctivitis usually comes with watery, tearing discharge, starts in one eye and moves to the other, and often follows a cold or contact with someone who was unwell. Bacterial conjunctivitis is marked by thick yellow-green pus that glues the lashes shut in the morning. Prominent itching in both eyes points instead to an allergic cause. When in doubt — and certainly if there is pain or any change in vision — get examined.
Does conjunctivitis require antibiotic drops? In most cases, no. Viral conjunctivitis — by far the most common type — does not respond to antibiotics at all and clears on its own within one to three weeks. Mild bacterial conjunctivitis also resolves by itself in most cases, though antibiotic drops can shorten it. Antibiotics matter mainly when the discharge is copious and purulent, in contact lens wearers, and in specific situations. Reaching for antibiotic drops for every red eye is a widespread and unnecessary habit.
How long is conjunctivitis contagious? Viral conjunctivitis is highly contagious — generally for as long as the eye is red and watering, which can be two weeks or more. Bacterial conjunctivitis is less contagious, and with antibiotic treatment infectivity drops substantially within a day or two. Allergic conjunctivitis is not contagious at all. Hand hygiene, separate towels and keeping hands away from the eyes are the core of prevention.
My child has conjunctivitis — when can they go back to school or nursery? With viral conjunctivitis it is best to stay home while there is active tearing and discharge, because it spreads through a nursery extremely fast. With bacterial conjunctivitis the accepted rule is returning about 24 hours after antibiotic treatment starts, once the discharge is settling. It is also worth remembering that recurrent infections or prolonged discharge in a child justify an examination — sometimes the cause is something else entirely, such as a blocked tear duct.
I have eye discharge but no redness — is that conjunctivitis? Not necessarily. Crusting or mild discharge in the morning without a genuinely red eye and without significant discomfort often comes from blepharitis (chronic eyelid inflammation) or from dry eye rather than from infectious conjunctivitis. If the discharge has gone on for weeks, the eyelids and ocular surface deserve a proper look — the treatment is completely different from treating an infection.
When is conjunctivitis an emergency? When there is real pain (as opposed to burning and itching), strong light sensitivity, any change in vision, copious purulent discharge, or when the person wears contact lenses — where the concern is corneal infection, a far more dangerous condition. Newborns in their first month of life with a red, discharging eye are also examined urgently. In any of these situations you do not wait to ‘see if it passes’ — you get examined.
