Conjunctivitis in the Eyes: 7 Questions Patients Often Ask Eye Specialists

Waking up with a red, sticky eye that won’t stop watering is never pleasant. The mirror reveals an alarming sight, and suddenly a dozen questions flood in. Should this be ignored? Could it spread? Is work out of the question today?

In England alone, infective conjunctivitis in the eye is one of the most common eye conditions seen in primary care, affecting around 13 to 14 people per 1,000 each year, roughly 1% of all GP consultations. This blog addresses the important questions eye specialists are most often asked by patients who walk in with pink eyes. Knowing what to expect from the condition can help identify symptoms early, prevent spread, and support timely recovery.

Please note: The information provided here is for general educational purposes and does not replace professional medical advice. If you experience persistent redness or irritation in your eyes, schedule a comprehensive eye examination at AccuVision to assess your eye health and identify any underlying causes of discomfort.

1. What Exactly Is Conjunctivitis in the Eye?

The conjunctiva is a thin, protective membrane that covers the white part of the eye and lines the inside of the eyelids. When this membrane becomes inflamed, it leads to a condition called conjunctivitis, commonly known as pink eye.

The redness occurs when blood vessels in the eye expand in response to irritation or infection. However, not all cases of conjunctivitis look or behave the same. Viral infections cause one type, bacteria trigger another, and allergens or irritants lead to their own distinct forms.

The discharge, discomfort, and duration vary considerably depending on what’s causing the inflammation. Watery eyes with mild itching usually indicate a viral or allergic cause, while thick yellow discharge is more typical of a bacterial infection.

2. Can You Get Conjunctivitis in Just One Eye?

Conjunctivitis in the eye often starts in a single eye, particularly when caused by infection. Someone might touch a contaminated door handle, then unconsciously rub one eye. That eye develops conjunctivitis while the other remains clear, at least initially.

Bacterial forms typically begin in one eye before potentially spreading to the other within a few days. Viral conjunctivitis in one eye behaves similarly, though it tends to move faster, sometimes affecting the second eye within 24 to 48 hours.

Allergic conjunctivitis in one eye is less common. Because allergens like pollen or dust affect both eyes simultaneously, allergic forms usually appear in both eyes at once. This distinction helps doctors work out what’s causing the problem.

Hands carry infection from one eye to the other more often than people realise. Separate towels, resisting the urge to rub, and frequent handwashing make a real difference in keeping the infection contained.

What Are the Common Symptoms of Conjunctivitis in the Eye?

The symptoms of conjunctivitis in the eye vary, though certain features remain common across different types. Redness is almost universal, along with that annoying sensation of grittiness.

Beyond these usual symptoms, the presentation shifts depending on the cause:

• Discharge: Clear, watery discharge suggests viral infection. Thick, yellow or green discharge indicates bacteria and stringy mucus often accompanies allergies
• Itching: Particularly intense with allergic forms. Viral and bacterial types cause more burning than itching.
• Crusty eyelids: Especially noticeable first thing in the morning when bacterial conjunctivitis is present.
• Tearing: Excessive watering occurs with both viral infections and allergies.
• Light sensitivity: Mild discomfort in bright conditions is common, though severe photophobia (increased sensitivity to light) needs urgent attention.

Some symptoms warrant immediate professional assessment. Significant pain, vision that stays blurred even after wiping away discharge, intense light sensitivity, or alarming redness all fall into this category.

4. What Causes Conjunctivitis?

Four main culprits trigger conjunctivitis: viruses, bacteria, allergens, and irritants.

• Viral infections: Approximately 80% of conjunctivitis cases in adults stem from viral infections, with adenoviruses responsible for the majority. These same viruses cause colds and respiratory infections, which explains why pink eye often arrives alongside a sniffle and sore throat.
• Bacterial infections: Various bacteria can inflame the conjunctiva, typically producing a characteristic thick, coloured discharge. Bacterial conjunctivitis is seen more frequently in children than in adults, with studies indicating that over half of childhood conjunctivitis cases may have a bacterial cause.
• Allergens: Allergic conjunctivitis affects an estimated 15% to 40% of people at some point, depending on factors like season, environment, and individual sensitivity. Pollen, dust mites, pet dander, and moulds top the list of triggers.
• Irritants: They range from chlorine in swimming pools to smoke, chemical fumes, or harsh cosmetics. Contact lens wearers sometimes develop irritant conjunctivitis from wearing lenses too long or not cleaning them properly.

The crucial distinction between these types is that only viral and bacterial forms spread from person to person. Allergic and irritant forms won’t transfer to anyone else, regardless of contact.

5. How Is Conjunctivitis Diagnosed and Treated?

Eye specialists typically diagnose conjunctivitis through physical eye examination rather than testing. The appearance of the eye, type of discharge, and accompanying symptoms usually paint a clear picture.

Treatment varies considerably depending on the type:

• Viral conjunctivitis usually ends up frustrating the patients because there’s no quick fix. Because there’s no specific antiviral treatment for common viral conjunctivitis, treatment focuses on comfort measures like artificial tears, cool compresses, and patience. The infection typically clears within one to two weeks.
• Bacterial forms respond to antibiotic eye drops or ointments. Treatment shortens the duration and allows people to return to work or school sooner. The drops typically need applying several times daily for about a week.
• Allergic conjunctivitis improves with antihistamine drops and avoiding triggers when possible. Cold compresses offer relief, and over-the-counter options work well for mild cases.
• Irritant conjunctivitis resolves once the irritating substance is removed. Usually, thorough eye rinsing, artificial tears, and patience are effective treatments

Self-prescribing carries risks, particularly with steroid drops. Steroids can worsen certain infections dramatically if used inappropriately. AccuVision’s specialists examine each case individually, ensuring the treatment matches the condition.

6. Is Conjunctivitis in One Eye or Both?

The question of whether conjunctivitis affects one eye or both provides clues about the cause. Infections commonly begin in one eye before transferring to the other after a day or two, with the first eye typically remaining more severely affected.

Preventing spread from an affected eye to its neighbor requires discipline. Touching or rubbing the infected eye, then touching the healthy one, carries the virus or bacteria across. Separate towels and pillowcases help, as does resisting the urge to rub itchy, uncomfortable eyes.

7. How Can You Prevent Conjunctivitis in the Eye?

Prevention beats treatment every time. Several practical measures significantly reduce risk.

• Hand hygiene tops the list. Regular handwashing, particularly before touching the face, prevents transmission. Fifteen seconds with soap and water, paying attention to fingertips and under nails, makes a real difference.
• Personal items shouldn’t be shared. Towels, pillowcases, eye cosmetics, and contact lens equipment all have the potential to spread infection. Makeup should be replaced every few months.
• Contact lens care requires attention. Proper cleaning routines, adhering to replacement schedules, and never sleeping in lenses prevent many cases. Cases themselves need regular cleaning and should be replaced every three months.
• Allergen avoidance helps when triggers are known. Wraparound sunglasses keep pollen away from eyes during high-count days. Keeping windows closed and showering after being outdoors reduces exposure.
• Staying home when contagious protects others. Viral conjunctivitis remains infectious for 10 to 14 days from symptom onset. Bacterial forms become non-infectious within 24 hours of starting antibiotic treatment.eyes.

Summary and Takeaway

Conjunctivitis disrupts daily life and causes significant discomfort, but understanding the condition helps people navigate episodes with less anxiety and better outcomes.

Viral forms clear with time and supportive care. Bacterial cases respond to antibiotics. Allergic types improve with antihistamines and trigger avoidance. Each follows its own course, but all benefit from proper hygiene.

Self-diagnosis carries risks though. What appears to be straightforward pink eye occasionally turns out to be something requiring different management. Professional assessment provides certainty and ensures the approach matches the actual condition.

This content was reviewed by the clinical team at AccuVision The Eye Clinic, a trusted UK-based centre for comprehensive laser vision correction and specialised eye care. With expert Ophthalmologists and Optometrists across the UK, AccuVision ensures that every article reflects accurate, medically reviewed information and supports evidence-based eye health awareness. This content is for general educational purposes only and should not be construed as medical advice. Always consult a qualified eye care professional for personalised guidance and treatment of specific conditions.

Frequently Answered Questions (FAQs)

1. Can you get conjunctivitis in one eye only?
Yes, you can get conjunctivitis in one eye, especially when it’s caused by viral or bacterial infection. It may later spread to the other eye if hygiene isn’t maintained.

2. What are the main causes of conjunctivitis in the eye?
Common causes include viral and bacterial infections, allergies, and irritants such as smoke or chlorine. Identifying the cause helps guide proper treatment.

3. How to prevent conjunctivitis in the eye from spreading?
Good hygiene is key; wash your hands often, avoid touching your eyes, and don’t share towels or cosmetics. These simple steps help prevent conjunctivitis from spreading.

4. Is conjunctivitis in one eye or both?
It often starts in one eye and can spread to the other within a few days. Allergic conjunctivitis usually affects both eyes at the same time.

5. How long does conjunctivitis usually last?
Viral cases clear in about one to two weeks, bacterial types improve within a few days of treatment, and allergic conjunctivitis settles once triggers are removed.

References:

Lewis, N. & Bhogal-Bhamra, G., 2023. Bacterial conjunctivitis: diagnosis and management. The Pharmaceutical Journal, 306(7950). Available at: https://pharmaceutical-journal.com/article/ld/bacterial-conjunctivitis-diagnosis-and-management [Accessed 11 November 2025].

Azari, A.A. & Barney, N.P., 2013. Conjunctivitis: a systematic review of diagnosis and treatment. JAMA, 310(16), pp. 1721-1729. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049531/ [Accessed 11 November 2025].

Hashmi, M. F. & Gurnani, B., 2024. Conjunctivitis. In: StatPearls [online]. Treasure Island (FL): StatPearls Publishing. Available at: https://www.ncbi.nlm.nih.gov/books/NBK541034/ [Accessed 11 November 2025].

Vidal Villegas, B. & Benítez-del-Castillo, J.M., 2021. ‘Current knowledge in allergic conjunctivitis’, Turk J Ophthalmol, 51(1), pp. 45-54. Available at: https://oftalmoloji.org/articles/current-knowledge-in-allergic-conjunctivitis/doi/tjo.galenos.2020.11456/ [Accessed 11 November 2025].