Dry eye syndrome

Lore & Background

Dry eye syndrome was the former name for what is now called dry eye disease (DED). The condition occurs when the eye does not produce enough tears or when tears evaporate too quickly. Symptoms include dryness, irritation, redness, discharge, blurred vision, and easily fatigued eyes, ranging from mild and occasional to severe and continuous. The phrase 'keratoconjunctivitis sicca' means 'dryness of the cornea and conjunctiva' in Latin.

Reader's Guide

The significance of dry eye syndrome lies in its evolution from a loosely defined syndrome to a recognized disease. The Tear Film & Ocular Surface Society Dry Eye Workshop (TFOS DEWS) II report in 2017 defined dry eye as a multifactorial disease of the ocular surface characterized by loss of homeostasis of the tear film. The TFOS DEWS III in 2025 updated the definition to emphasize the intrinsic role of both ocular surface tissues and the tear film. These definitions have helped establish clear diagnostic features, natural history, and therapeutic responses. Treatment depends on the underlying cause, with artificial tears as first-line therapy. The condition affects 5–34% of people, with higher rates among older populations. Its legacy includes improved understanding of tear film instability, hyperosmolarity, ocular surface inflammation, and neurosensory abnormalities as etiological factors.

Did You Know?

• Dry eye syndrome was formerly used but is now avoided following advances that established it as a distinct disease entity.
• Symptoms can include a stringy discharge from the eyes and excessive tearing due to irritation.
• About half of all people who wear contact lenses complain of dry eyes.
• The phrase 'keratoconjunctivitis sicca' means 'dryness of the cornea and conjunctiva' in Latin.

From Syndrome to Disease — A Shift in Medical Identity

The condition long carried the label "dry eye syndrome," a term that implied a loose collection of symptoms without a clear underlying mechanism. That framing began to shift as research deepened. The Tear Film & Ocular Surface Society Dry Eye Workshop (TFOS DEWS) II report in 2017 offered a multidisciplinary, transnational committee's definition that positioned dry eye as a multifactorial disease of the ocular surface, marked by a loss of tear film homeostasis. It named tear film instability, hyperosmolarity, ocular surface inflammation, and neurosensory abnormalities as etiological players. By 2025, TFOS DEWS III confirmed the core definition needed no radical overhaul but refined the language to emphasize the intrinsic role of both ocular surface tissues and the tear film in maintaining balance. This progression from "syndrome" to "disease" reflects a broader maturation: what was once a vague cluster of complaints now has clarified diagnostic features, a natural history, and recognized therapeutic responses, cementing its status as a distinct clinical entity. The Latin name keratoconjunctivitis sicca—meaning dryness of the cornea and conjunctiva—remains in use alongside the modern terminology.

The Paradox of a Dry Eye That Waters

The lived experience of dry eye disease is full of contradictions that confuse sufferers. A person may feel a sandy, gritty irritation that intensifies as the day wears on, accompanied by burning, stinging, a pulling sensation, or pressure behind the eye. Many describe the persistent feeling that a speck of dirt is lodged in the eye, even when no foreign body is present. Yet the very condition that leaves the surface parched can trigger reflex tearing—excessive, watery discharge that offers no relief because those tears lack the lubricating qualities the ocular surface needs. Both eyes are typically affected, and the resulting surface damage heightens discomfort and sensitivity to bright light. Symptoms are amplified by anything that reduces blinking: prolonged reading, computer work, driving, or watching television. Windy, dusty, smoky, or arid environments, high-altitude travel, low-humidity days, and the airflow from air conditioners, fans, heaters, or hair dryers all worsen the picture. Conversely, cool, rainy, foggy weather or the humidity of a shower can bring temporary ease.

Why It Happens — A Tangle of Causes

Dry eye arises through two fundamental pathways: the eye fails to generate sufficient tears, or the tears it does produce evaporate too rapidly. A wide web of contributors feeds into either mechanism. Aging stands out as one of the most common factors, since tear production naturally declines over a lifetime. Contact lens wear, meibomian gland dysfunction, pregnancy, Sjögren's disease, vitamin A deficiency, and omega-3 fatty acid deficiency all figure prominently. Surgical interventions such as LASIK can disrupt the balance, and chronic conjunctivitis from tobacco smoke or infection may tip the scales. A notable cluster of medications—antihistamines, certain blood pressure drugs, hormone replacement therapy, antidepressants, and anticholinergics—has been linked to the condition, particularly in older adults who often take multiple prescriptions. Excess screen time compounds the problem: while a person normally blinks around fifteen times per minute, studies show the rate drops to five or seven blinks per minute during computer or smartphone use, depriving the surface of the moisture coating each blink delivers. Prevalence is substantial, affecting five to thirty-four percent of people depending on the population studied, climbing to as high as seventy percent among older individuals, and roughly seventeen percent in China.

Managing the Condition — From Drops to Lifestyle Adjustments

Treatment is tailored to whatever underlying cause is driving the problem. For most patients, the first step is simple: artificial tears to replenish lubrication. Wrap-around glasses that sit close to the face can reduce how quickly tears evaporate from the surface. If a medication is the culprit, a careful review of the prescription list—and a safe adjustment in consultation with a physician—may ease symptoms. Topical eye drops and other medications may be prescribed for more persistent cases. The immunosuppressant cyclosporine (ciclosporin) can be recommended to stimulate tear production, while short courses of topical corticosteroids sometimes help quiet inflammation. Diagnosis itself leans heavily on the patient's reported symptoms, though additional tests can supplement the clinical picture. In severe or untreated cases, the condition can progress to corneal scarring, neurosensory changes, impaired or even lost vision, and instability of the tear film. For some individuals, dry eye becomes so pronounced that wearing contact lenses is no longer feasible. Most people, however, experience only mild irritation without long-term sequelae, making early recognition and consistent management the key to keeping the condition in check.

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