Inflamed Eyes (Conjunctivitis) - Causes, Treatment & When to See a Doctor

What is Inflamed Eyes (Conjunctivitis)?

Conjunctivitis, commonly called “pink eye” or “inflamed eyes,” is the irritation and redness of the conjunctiva—the thin, transparent membrane that lines the inside of the eyelids and covers the white part of the eye (the sclera). When the conjunctiva becomes inflamed, blood vessels expand, giving the eye a pink or reddish hue. The condition can affect one eye or both and is usually not sight‑threatening, but it can be uncomfortable and highly contagious when caused by infectious agents.

Common Causes

Conjunctivitis can be grouped into three main categories: infectious, allergic, and irritant (non‑infectious). Below are the most frequent triggers.

• Viral infection – Adenoviruses are the leading cause; other viruses (herpes simplex, enterovirus) can also be responsible.
• Bacterial infection – Common culprits include Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
• Allergic reaction – Pollen, dust mites, pet dander, and seasonal allergens trigger an immune response.
• Chemical or environmental irritants – Smoke, chlorine (swimming pools), air pollutants, or accidental exposure to cleaning agents.
• Contact lens wear – Improper cleaning, overnight wear, or a broken lens can introduce bacteria.
• Dry eye syndrome – Insufficient tear production can lead to inflammation of the conjunctiva.
• Autoimmune diseases – Conditions such as Sjögren’s syndrome or rheumatoid arthritis may cause chronic conjunctival inflammation.
• Foreign bodies – Dust, eyelashes, or small particles that scratch the conjunctiva.
• Neonatal conjunctivitis – Acquired during birth from maternal infection (e.g., Chlamydia trachomatis or Neisseria gonorrhoeae).
• Systemic medication side effects – Certain drugs (e.g., isotretinoin, prostaglandin analogues) can cause ocular surface inflammation.

Associated Symptoms

While the hallmark sign is redness, several other symptoms often accompany conjunctivitis. Their presence can help differentiate the cause.

• Eye discharge – watery (viral/allergic) or thick yellow/green (bacterial).
• Itching or burning sensation – classic for allergic conjunctivitis.
• Sensitivity to light (photophobia).
• Gritty feeling, as if there is sand in the eye.
• Swollen eyelids.
• Crusting of lashes, especially upon waking.
• Blurred vision that resolves after blinking.
• Feeling of fullness or pressure around the eye.

When to See a Doctor

Most cases of conjunctivitis are mild and resolve with simple care, but certain situations warrant professional evaluation:

• Symptoms last longer than 7–10 days without improvement.
• Intense pain, severe headache, or a sensation of “eye pressure” (could indicate glaucoma).
• Marked swelling of the eyelid or a swollen, tender area around the eye.
• Vision becomes noticeably blurry or double.
• Yellow or green discharge that is copious or persistent.
• History of recent eye trauma, surgery, or contact‑lens complications.
• Neonates or infants develop redness, discharge, or swelling – this can progress rapidly.
• Systemic symptoms such as fever, sore throat, or a rash develop alongside eye changes.
• If you suspect a sexually transmitted infection (e.g., gonorrhea, chlamydia) causing conjunctivitis.

Diagnosis

Evaluation typically includes:

1. Medical history – Onset, exposure to sick contacts, recent allergies, contact‑lens use, and systemic illnesses.
2. Physical examination – Visual acuity test, inspection of the eyelids, cornea, and conjunctiva using a slit‑lamp microscope.
3. Eye discharge sampling – Swab of the conjunctival secretions can be sent for Gram stain, culture, or PCR to identify bacterial or viral agents, especially in severe or atypical cases.
4. Allergy testing – If allergic conjunctivitis is suspected, skin‑prick or serum IgE testing may be recommended.
5. Additional tests – In rare chronic cases, fluorescein staining, Schirmer test (tear production), or imaging (e.g., B‑scan ultrasound) may be ordered.

Most primary‑care or ophthalmology visits rely on clinical observation; laboratory testing is reserved for atypical or refractory presentations.

Treatment Options

Medical Therapies

• Antiviral medication – Reserved for herpes simplex conjunctivitis (e.g., topical trifluridine or oral acyclovir).
• Antibiotic eye drops or ointments – Fluoroquinolones, macrolides, or sulfonamides are used for bacterial conjunctivitis, especially in contact‑lens wearers or when the infection is severe.
• Anti‑allergic drops – Mast‑cell stabilizers (e.g., olopatadine, ketotifen) relieve itching and redness in allergic conjunctivitis.
• Corticosteroid eye drops – Short‑course steroids may be prescribed for severe inflammation or for specific causes (e.g., uveitis‑associated conjunctivitis) under close supervision.
• Artificial tears – Preservative‑free lubricants soothe irritation in viral, allergic, or dry‑eye‑related cases.

Home & Self‑Care Measures

• Apply a clean, cold compress to the closed eyelid for 5–10 minutes, several times a day, to reduce swelling.
• Practice strict hand‑washing before and after touching the eyes.
• Avoid rubbing the eyes; use a tissue to gently wipe away discharge.
• Discard or replace contaminated eye makeup, contact lenses, and lens cases.
• Use over‑the‑counter antihistamine eye drops for mild allergic symptoms.
• Maintain a humid environment (e.g., humidifier) if dry air worsens the irritation.

Prevention Tips

• Hand hygiene – Wash hands with soap and water for at least 20 seconds frequently.
• Avoid sharing personal items – Towels, pillowcases, eye makeup, and contact‑lens solutions should be personal.
• Proper contact‑lens care – Follow the cleaning regimen recommended by your eye‑care professional; replace lenses and cases as advised.
• Use protective eyewear – When swimming, wear goggles to keep chlorine out of the eyes.
• Allergy control – Keep windows closed during high pollen days, use HEPA filters, and wash bedding weekly.
• Stay up‑to‑date on vaccinations – The adenovirus vaccine is not routinely given, but good overall immunity helps lower viral eye infections.
• Neonatal care – Provide prophylactic erythromycin eye ointment to newborns as recommended by the CDC.
• Environmental cleanliness – Disinfect surfaces (doorknobs, keyboards) regularly during outbreaks of viral conjunctivitis.

Emergency Warning Signs

References

Information in this article is based on current guidelines and peer‑reviewed sources, including:

• Mayo Clinic. “Conjunctivitis (pink eye).” 2024. mayoclinic.org
• Centers for Disease Control and Prevention. “Conjunctivitis.” 2023. cdc.gov
• National Eye Institute, NIH. “Conjunctivitis.” 2022. nei.nih.gov
• Cleveland Clinic. “Pink Eye (Conjunctivitis) Causes, Symptoms, and Treatment.” 2024. clevelandclinic.org
• World Health Organization. “Prevention of Ocular Infections.” 2023. who.int