Dry Eye Disease (DED) is a common condition characterized by discomfort, stinging, redness, and sometimes blurry vision resulting from a tear film that cannot adequately lubricate the eye’s surface. While tears are mostly water, their stability is complex. Systemic hydration supports the production of high-quality tears, offering a foundational element of relief for many sufferers, though the impact is indirect and depends on the specific cause of the dryness.
The Direct Link Between Systemic Hydration and Tear Volume
The body’s overall hydration level directly influences the watery component of your tears, known as the aqueous layer, which is primarily secreted by the lacrimal glands. When the body is dehydrated, the concentration of solutes in the blood increases. The body attempts to maintain fluid balance by drawing water from various sources, affecting the composition of the fluid secreted by the lacrimal glands.
This systemic dehydration leads to tears that are saltier, or hyperosmolar, a key characteristic and driver of DED. Hyperosmolar tears irritate the delicate surface of the eye, triggering inflammation and discomfort. Studies have indicated a connection between individuals classified with dry eye and those exhibiting suboptimal hydration. Drinking water helps normalize the body’s internal fluid balance, supporting the lacrimal glands in producing a sufficient volume of less concentrated, more soothing tears.
Causes of Dry Eye Disease Beyond Water Intake
While systemic hydration affects the volume of the watery tear layer, most cases of DED stem from a problem with the quality and stability of the tear film. This is known as evaporative dry eye, and it accounts for the majority of diagnoses. The tear film naturally includes an outer oily layer that acts like a seal, preventing the underlying aqueous layer from evaporating too quickly.
This oily layer is produced by specialized glands located in the eyelids called meibomian glands. Dysfunction of these glands (MGD) is the most common cause of evaporative DED, meaning tears disappear rapidly even if the lacrimal glands are producing enough aqueous fluid. In these instances, simply drinking more water will not fix the defective oil layer.
Environmental factors also significantly contribute to tear evaporation. Exposure to windy conditions, dry climates, or low-humidity environments like airplane cabins can rapidly destabilize the tear film. Reduced blinking rates, a common behavior during prolonged screen time, also increases evaporation and worsens symptoms. Furthermore, certain medications, including some antihistamines and antidepressants, can reduce tear production as a side effect, causing dryness that requires medical management beyond simple hydration.
Actionable Hydration and Environmental Strategies for Relief
For individuals with DED, incorporating consistent hydration is a foundational step in management. A general guideline suggests aiming for approximately eight to ten glasses of water daily, though specific needs vary based on body size, activity level, and climate. It is helpful to reduce intake of beverages like alcohol and excessive caffeine, which have dehydrating effects that can counteract efforts to improve systemic fluid balance.
Environmental adjustments provide immediate, local support for tear film stability. Using a humidifier, especially in bedrooms or offices with dry air from heating or air conditioning, adds moisture to the surrounding environment, slowing tear evaporation. When focusing on screens, practicing the 20-20-20 rule—looking at something 20 feet away for 20 seconds every 20 minutes—encourages regular, full blinking, which helps spread the tear film evenly.
Over-the-counter artificial tears offer local supplementation to the tear film for quick, temporary relief. They provide immediate moisture to the eye’s surface, complementing the long-term, systemic benefits of adequate water intake. If dryness symptoms persist despite consistent hydration and lifestyle adjustments, consulting an eye care professional is recommended to address underlying issues like MGD or inflammation, which often require prescription treatments.