Ocular dehydration, commonly referred to as dry eye, occurs when the eye surface lacks adequate moisture or a stable tear film to remain lubricated. The tear film is a complex layer of fluid that coats the cornea. This condition is common and can be a temporary response to environmental or behavioral factors. When the body conserves water due to insufficient hydration, the eyes are often one of the first areas to show a fluid deficiency.
The Visual and Sensory Signs of Ocular Dehydration
Eyes that lack proper hydration often lose their natural luster, displaying a subtle dullness. A lack of lubrication causes irritation, which frequently manifests as mild redness, often most noticeable around the edges of the eye. Systemic dehydration can also cause the skin and tissue around the eyes to lose volume, sometimes leading to a slightly sunken or hollowed appearance.
Ocular dehydration often begins with a foreign body sensation described as feeling like sand or grit in the eye. This feeling is usually accompanied by a burning or stinging discomfort that worsens throughout the day. Because the tear film provides a smooth surface for light refraction, its instability can cause temporary or fluctuating blurry vision. The irritated ocular surface can also become sensitive to bright light, a condition known as photophobia.
Underlying Causes and Contributing Factors
A primary cause of this condition is insufficient systemic water intake, as tears are primarily composed of water. When the body is dehydrated, tear production slows and volume is reduced, leading to an overly concentrated tear film. Environmental elements significantly contribute to rapid tear evaporation, including exposure to high winds, low-humidity air, or forced air from heating and air conditioning units.
Behavioral habits also play a large role in promoting ocular dryness, particularly the reduced blinking rate associated with prolonged screen time. When focusing intensely on digital devices or reading, people blink less frequently, preventing the tear film from being regularly refreshed. Certain medications, such as antihistamines and decongestants, are known to decrease tear production as a side effect. Chronic issues like Sjögren’s syndrome or diabetes can also disrupt the body’s ability to maintain a healthy tear film.
Immediate Relief and Prevention Strategies
For immediate comfort, the use of over-the-counter lubricating eye drops, often called artificial tears, can temporarily supplement the eye’s natural moisture. Consciously increasing the rate of blinking helps spread the existing tear film across the eye surface more evenly. Taking frequent breaks from screens by following the 20-20-20 rule—looking at something 20 feet away for 20 seconds every 20 minutes—can also encourage the eyes to rest and re-lubricate.
Long-term prevention involves maintaining proper whole-body hydration, with a suggestion of consuming eight to ten glasses of water daily. Using a humidifier in dry indoor environments adds moisture to the air, which slows tear evaporation. Adjusting the workstation so the computer screen is positioned slightly below eye level minimizes the exposed surface area of the eye, reducing the rate of tear loss.