Everything you need to know about conjunctivitis

Woke up with gooey, stuck-together eyelids and a pink tinge to your eye? That's almost always conjunctivitis, the eye condition most of us just call pink eye. It means the conjunctiva is inflamed (the thin, clear film over the white of your eye and the inside of your lids). [1] It's one of the most common eye problems an optician sees, and the good news is that most cases are mild and clear on their own within a week or two. This guide covers what causes it, how it looks and feels, how to treat it, and when to get your eyes checked.

What causes it?

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If you've caught pink eye, the first job is to work out which type you have. There are three, and each one has a different cause and a different fix. Two are infections that spread from person to person, and the third is an allergic reaction you cannot catch. Knowing which type you have tells you what to do next. Symptoms are usually worst in the first day or two, then start to settle.

Bacterial conjunctivitis

Bacterial conjunctivitis is just what it sounds like: bacteria infect the surface of the eye. Both eyes often turn red and gritty, with a sticky yellow or green discharge that glues your lashes together. [1] It spreads fast through your hands, shared towels, and pillowcases, so wash your hands often and keep your own towel while it clears.

Allergic

The allergic type is not an infection, so you cannot catch it or pass it on. Your eyes are simply reacting to an allergen, such as pollen, dust, or pet dander. [1] Both eyes itch, water, and puff up at once. It often comes with hay fever or asthma, and it can be seasonal or last all year. Find the trigger, stay away from it, and the flare settles.

Viral

Viral conjunctivitis comes from the same everyday viruses as a common cold. The most common cause is an adenovirus, according to the Centers for Disease Control and Prevention. [2] It's very contagious, and it passes on through coughs, sneezes, and touch. It often starts in one watery eye, then spreads to the other a day or two later.

Symptoms of pink eye

You usually see the signs before you feel much. The white of the eye turns pink or red as tiny blood vessels swell, which is exactly where the name comes from. [1] Here is what most people notice:

• The white of one or both eyes turns pink or red and looks glassy.
• Watery or sticky discharge that gums your lashes together overnight.
• A gritty, burning, or itchy feeling, as if grit is stuck under the lid.
• Puffy, swollen eyelids, sometimes with mild sensitivity to bright light.
• Crusting along the lash line, worst first thing in the morning.

The mix depends on the type. The bacterial form brings thick, sticky discharge, while the viral form waters constantly and the allergic form itches without let-up. [1]

Pink eye with flu-like symptoms

Sometimes it turns up with a heavy cold, and that's no coincidence. The viral type often occurs along with a cold or a respiratory infection. So it can come with symptoms such as a sore throat. [2] This is the version people usually mean when they search for pink eye with flu-like symptoms. The eye itself often flares a day or two after the sniffles start. Antibiotics do nothing against a virus, so most cases simply clear on their own within one to two weeks. [2] To ease it, hold a cool, damp flannel over closed eyes. A lubricating drop such as Clinitas Soothe eases gritty, irritable eyes. Its re-sealable vials keep for up to 12 hours once opened. It's worth keeping a few rewetting and lubricating eye drops on hand.

Eyelid swelling with pink eye

Swollen, puffy eyelids are one of the most common signs of pink eye. The Cleveland Clinic says the infection often makes the lids look puffy or droopy, which is why the whole eye can look half-closed. [4] Eyelid swelling can happen with any type, but it is usually worst with the allergic form, when the lids balloon and itch at once. A cool compress brings the puffiness down, and for the allergic kind an antihistamine drop (which calms the reaction) settles things. Watch for the warning signs, though. If you have moderate-to-severe eye pain, your vision blurs, or bright light becomes hard to bear, see an optician or your GP without delay. [3] And if the swelling spreads across your face, or you feel unwell, get same-day advice.

Most cases need very little treatment, which can feel like a relief when your eye looks alarming in the mirror. The bacterial type usually clears within a week on its own. If it does not, a pharmacist can give you chloramphenicol (an antibiotic you buy without a prescription) as drops or ointment. [1] The viral form has no antibiotic cure, so you simply ease the symptoms while the virus passes. Give it a day or two before you expect real improvement. For the allergic type, the fix is to avoid the trigger, with antihistamine drops to fall back on. A lubricating drop like Systane Ultra takes the edge off the grittiness. One rule holds for every type: never share drops or a flannel used on an infected eye.

Risk factors

Anyone can get it, but a few things raise the odds. You're more likely to catch the infective kind if you've been near someone who has it, or soon after a cold. The two infective types are very contagious. [1] Long-term eyelid inflammation (blepharitis) and a weaker immune system make you more prone too. Contact lens wearers need extra care, because lenses trap bacteria against the eye and a scratched or over-worn lens lets infection in. If your eyes are red or sore, take your lenses out, and leave them out until an optometrist gives you the all-clear. [5]

Top tips

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No one likes passing an eye infection around the whole house, and the two infective types spread easily. A few simple habits keep things contained. Wash and dry your hands well, especially before and after you touch your eyes. Use a fresh towel and pillowcase, and keep them to yourself. Try not to rub, which just moves the infection from one eye to the other. Wipe down shared surfaces like taps and phone screens.

Throw away the contact lenses, case, and solution you used when symptoms began, as they can hold onto bacteria. Once your eyes are fully clear, ease back in with a fresh pair of daily disposable lenses. For reusable lenses, start again with fresh contact lens solution. If your pink eye gets worse instead of better, keeps returning, or lasts more than a couple of weeks, book an eye examination. [3] For more everyday eye advice, our eye care guides are a good next stop.

Sources

[1] NHS (nhs.uk) — pink eye is another name for conjunctivitis; its main symptoms, causes, and how contagious the infective types are. Bacterial conjunctivitis often clears within a week, and a pharmacist can supply the antibiotic chloramphenicol.

[2] Centers for Disease Control and Prevention (cdc.gov) — viral conjunctivitis is most often caused by an adenovirus, can occur along with a cold or a respiratory infection such as a sore throat, and usually clears on its own within one to two weeks.

[3] American Academy of Ophthalmology (aao.org) — see an ophthalmologist if pink eye comes with moderate-to-severe eye pain, blurred vision, increased light sensitivity, or intense redness, if it gets worse instead of improving, or if it lasts more than one to two weeks.

[4] Cleveland Clinic (my.clevelandclinic.org) — pink eye can make the eyelids look puffy or droopy.

[5] College of Optometrists (college-optometrists.org) — remove your contact lenses and get prompt advice from your optometrist if your eyes are red, sore, or discharging.