Not all eye drops are the same—confusing an eye lubricant with a medicated eye drop can delay necessary treatment. Lubricating eye drops (artificial tears) contain thickening agents— sodium hyaluronate (0.1 to 0.3%), carmellose, carbomer—that restore the tear film without treating an infectious or allergic condition. Medicated eye drops (antibiotics, anti-inflammatories, antihistamines) contain active ingredients with pharmacological effects and require a prescription or advice from a pharmacist. Bacterial conjunctivitis that is not treated with an appropriate antibiotic can progress to keratitis—an ophthalmologist’s consultation is essential if there is any doubt.
The presence of vitamin B12 (cyanocobalamin or methylcobalamin at 0.05%) in new-generation lubricating eye drops is based on a specific neurobiological rationale. Corneal nerve fibers, among the densest in the human body (7,000 to 10,000 endings/mm²), depend on vitamin B12 for myelination and neuroprotection. Clinical studies (Bhartiya et al., 2015; Hwang et al., 2020) show that topical vitamin B12 supplementation improves regeneration of the corneal nerve plexus in severe dry eye syndromes. It also reduces sensitivity to chronic corneal pain—one of the best-documented benefits of next-generation artificial tears.
The tear film is a three-layered structure 3 to 10 µm thick: an outer lipid layer (Meibomian glands, prevents evaporation), an intermediate aqueous layer (lacrimal glands, 90% of the volume), and an inner mucin layer (goblet cells, which anchor the film to the cornea). Its instability—measured by tear breakup time (TBUT, normal ≥ 10 seconds)—is the primary cause of dry eye. When looking at a screen, blinking rate drops from 15–20 times per minute to 3–7 times per minute; evaporation accelerates in air-conditioned offices; and wearing contact lenses disrupts the mucin layer—a triple destabilizing factor.
Vitamin A (retinol, retinaldehyde) is the micronutrient most directly linked to the integrity of the corneal and conjunctival epithelium. Relative deficiencies (strict veganism, malabsorption, bariatric surgery) can lead to squamous metaplasia of the conjunctival epithelium—reducing mucin production and worsening dry eye. Vitamin A ophthalmic ointment is the standard treatment for severe keratoconjunctivitis sicca. Preventive oral intake: 700 to 900 µg retinol equivalent (RE) per day through the diet (liver, eggs, dairy products, beta-carotene).
Cornflower (Centaurea cyanus)floral water is the most widely used natural eye care product in France for eye fatigue and puffy eyelids. Its anthocyanins and flavonoids have documented anti-edematous and mildly astringent properties that promote comfort. It is intended for hygiene and comfort, not as a substitute for medical eye drops—persistent redness, eye pain, sensitivity to light, or decreased visual acuity require an immediate consultation with an ophthalmologist.
The instillation technique determines the product’s effectiveness and safety. After washing your hands, gently pull down the lower eyelid, instill one drop without touching the eyeball with the tip (risk of contamination), then close the tear duct for 1 to 2 minutes by applying gentle pressure to the inner corner—this step reduces systemic absorption by 50 to 70%, which is essential for eye drops containing beta-blockers or corticosteroids. Most multidose bottles should be used within 28 days after opening. In cases of conjunctivitis or for proper eye irrigation, the dedicated pages supplement this guide.
