on June 16, 2026
When a red eye is a sign that should not be underestimated
Conjunctivitis is one of the most common causes of “red eye” and is one of the most common eye conditions in clinical practice. In most cases, it is a benign and self-limiting condition, but correctly identifying the cause is essential for establishing the appropriate treatment and avoiding complications.
Eye redness, tearing, light sensitivity (photophobia), a foreign body sensation, and burning are very common symptoms, but they do not always indicate simple conjunctivitis. In the presence of severe pain, reduced vision, abundant discharge, or persistent symptoms, it is advisable to consult a doctor or ophthalmologist.
What is conjunctivitis
The conjunctiva is a thin, transparent membrane that covers the inner surface of the eyelids and the front part of the eyeball. When this structure becomes inflamed, it is called conjunctivitis.
The most common forms are:
Viral conjunctivitis
Bacterial conjunctivitis
Allergic conjunctivitis
Irritative conjunctivitis caused by physical or chemical agents
Each form has different characteristics and requires a specific approach.
Viral conjunctivitis: the most common form
Viral conjunctivitis accounts for a significant proportion of acute eye infections and is often caused by adenoviruses.
Typical symptoms include:
Marked redness
Abundant tearing
Clear serous discharge
Photophobia
Discomfort or a gritty sensation in the eyes
Transmission occurs easily through direct contact with contaminated secretions or unwashed hands. Contagiousness is high, especially in the first few days.
In most cases, treatment is supportive and aims to control symptoms through eye hygiene and lubrication.
Bacterial conjunctivitis: when purulent discharge appears
Bacterial forms are generally caused by bacteria such as Staphylococcus aureus, Streptococcus pneumoniae, and other opportunistic microorganisms.
The most characteristic signs include:
Thick yellow-green discharge
Eyelids stuck together upon waking
Eyelid swelling
Eye redness
Treatment may require antibiotic eye drops prescribed by a doctor, especially in confirmed or clinically suggestive cases.
Allergic conjunctivitis: the role of the immune system
Allergic conjunctivitis is not contagious and is frequently associated with allergic rhinitis.
The main triggers include:
Pollen
Dust mites
Animal dander
Environmental allergens
The distinguishing symptom is intense itching associated with tearing and bilateral redness.
Management includes reducing exposure to allergens and, when indicated, using antihistamine or anti-inflammatory eye drops.
Risk factors and daily prevention
Some habits may increase the risk of eye irritation or infection:
Frequently touching the eyes with unwashed hands
Incorrect use of contact lenses
Sharing towels or cosmetics
Exposure to smoke and polluted environments
Spending long hours in front of digital screens
To reduce the risk, it is useful to:
Wash your hands frequently
Use personal eye products
Avoid makeup during inflammation
Maintain proper contact lens hygiene
Take breaks while working on the computer
Diet, oxidative stress, and eye health
The eye is a tissue particularly exposed to oxidative stress.
Numerous studies suggest that a diet rich in:
Vitamin C
Vitamin E
Carotenoids (lutein and zeaxanthin)
Omega-3 fatty acids
Plant polyphenols
may help maintain normal visual function.
It is important to note that the AREDS and AREDS2 studies evaluated the role of supplementation in age-related macular degeneration, not in the prevention or treatment of conjunctivitis.
AREDS showed a reduction in the progression to advanced macular degeneration in selected high-risk subjects.
AREDS2 subsequently replaced beta-carotene with lutein and zeaxanthin and modified the nutritional profile to improve its benefit-risk ratio.
Phytotherapy and eye health: what evidence exists
Phytotherapy may provide complementary support for eye health without replacing medical treatment when necessary.
Among the plants traditionally used are:
Eyebright (Euphrasia officinalis) – traditionally used for eye comfort and relief from irritation.
Chamomile (Matricaria chamomilla) – known for its soothing and antioxidant properties.
Wren-run (Hamamelis virginiana) – used for its astringent effect.
Cornflower (Centaurea cyanus) – traditionally used in periocular cosmetic preparations.
Mallow (Malva sylvestris) – characterized by mucilage with an emollient effect.
However, high-quality clinical evidence on the use of phytotherapeutic preparations in conjunctivitis remains limited, and their use should be considered supportive.
Eye strain and computer work
Prolonged exposure to screens may contribute to the development of dry eye and eye strain.
Useful strategies include:
The 20-20-20 rule: every 20 minutes, look at an object about 20 feet (6 meters) away for 20 seconds
Increase blinking frequency
Optimize lighting and posture
Conclusions
Conjunctivitis is a very common condition, but not all forms are the same. Distinguishing between viral, bacterial, allergic, or irritative origins makes it possible to choose the most appropriate treatment.
Alongside proper medical therapies, daily hygiene, a balanced lifestyle, control of oxidative stress, and some phytotherapeutic support strategies can contribute to the health of the ocular surface.
In the presence of pain, worsening vision, or persistent symptoms, a specialist evaluation is always advisable.
Bibliography
Azari AA, Barney NP. Conjunctivitis: a systematic review of diagnosis and treatment. JAMA. 2013.
American Academy of Ophthalmology. Preferred Practice Pattern – Conjunctivitis.
AREDS Research Group. A randomized, placebo-controlled clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss. Arch Ophthalmol. 2001.
AREDS2 Research Group. Lutein + Zeaxanthin and Omega-3 Fatty Acids for Age-Related Macular Degeneration. JAMA. 2013.
Leonardi A. Management of ocular allergy. Curr Opin Allergy Clin Immunol. 2013.
Mantelli F et al. Dry eye disease and oxidative stress. J Cell Physiol. 2020.
EMA Assessment Report on Euphrasia officinalis preparations.
