Eye dryness happens when your tears can’t keep the surface of your eye properly lubricated. This can mean your eyes don’t produce enough tears, or the tears you do produce evaporate too quickly. The causes range from everyday habits like screen time to hormonal shifts, medications, and underlying health conditions.
How Your Tear Film Works
Your tear film has three layers, and a problem with any one of them can leave your eyes feeling dry, gritty, or irritated. The innermost layer is a mucin coating that helps tears stick evenly across the eye’s surface. The middle layer is mostly water, produced by the lacrimal glands above each eye, and makes up the bulk of what we think of as tears. The outermost layer is a thin film of oils, produced by tiny glands lining your eyelid margins called meibomian glands. That oil layer acts as a seal, slowing evaporation so your tears last between blinks.
When the oil layer is too thin or poor quality, tears evaporate faster than they should. When the lacrimal glands underperform, there simply isn’t enough water-based fluid to keep the surface wet. And when mucin production drops, tears can’t spread smoothly and instead bead up, leaving dry patches on the cornea.
Meibomian Gland Dysfunction
The single most common pathway to dry eyes is a problem with the meibomian glands. These glands can become clogged, inflamed, or gradually stop working, a condition called meibomian gland dysfunction (MGD). When the oil layer breaks down, tears evaporate off the eye surface far more quickly than normal. This is classified as evaporative dry eye, and it accounts for the majority of cases. You might notice it as a burning or stinging sensation that worsens as the day goes on, particularly in dry or windy environments.
Screen Time and Reduced Blinking
Every time you blink, your eyelids spread a fresh coat of tears across the eye. During focused tasks like reading a screen, your blink rate drops by roughly 50% compared to normal viewing. That means your tear film sits exposed for longer stretches, thinning and breaking apart before the next blink refreshes it. This is the core mechanism behind the dryness, fatigue, and irritation that come with long hours on computers, tablets, and phones. The effect is cumulative: a full workday of reduced blinking can leave your eyes noticeably uncomfortable by evening.
Low Humidity and Dry Environments
The air around you has a direct effect on how fast your tears evaporate. Research measuring tear loss found that when indoor humidity dropped from 40-45% to 20-25%, tear evaporation rates nearly doubled. Air conditioning, forced-air heating, airplane cabins, and high-altitude locations all push humidity well below that comfort zone. Someone whose dry eye is mild at sea level may find their symptoms flare significantly at altitude, where the air is both drier and thinner. Wind compounds the problem by sweeping moisture off the eye surface even faster.
Medications That Reduce Tear Production
Several common medication classes interfere with tear production as a side effect. Antihistamines, which are designed to dry out mucous membranes to relieve allergies, don’t limit that drying effect to your nose. Antidepressants, blood pressure medications, corticosteroids, and nonsteroidal anti-inflammatory drugs can all contribute to dry eyes. If your symptoms appeared or worsened around the time you started a new medication, the timing is worth noting. In many cases, switching to an alternative drug or adjusting the dose can help, though that’s a conversation to have with whoever prescribed it.
Hormonal Changes and Menopause
Dry eye is significantly more common in women, and hormones are a major reason why. The meibomian glands and lacrimal glands both have sex hormone receptors. Androgens (often thought of as male hormones, though women produce them too) stimulate the meibomian glands to produce the protective oil layer. When androgen levels decline during menopause, lipid production drops, and tears evaporate more readily.
Estrogen’s role is more complicated. Rather than helping, estrogen actually decreases lipid production from the meibomian glands. This helps explain why hormone replacement therapy focused on estrogen alone doesn’t reliably improve dry eye and can sometimes make it worse. Research on men taking androgen-blocking medications and individuals with complete androgen insensitivity syndrome has confirmed higher rates of dry eye, reinforcing the link between androgen levels and tear film stability.
Autoimmune Conditions
Sjögren’s syndrome is the autoimmune disease most closely associated with dry eyes. In this condition, immune cells infiltrate and gradually destroy the lacrimal and salivary glands, producing the hallmark combination of dry eyes and dry mouth. The damage is progressive: immune cells cluster around the gland’s ducts, disrupting their structure and reducing secretion. Over time, the glands can atrophy. Inflammatory molecules released during this process also break down the tight junctions between cells in the gland tissue, further impairing their ability to function.
Sjögren’s can occur on its own (primary) or alongside another autoimmune disease (secondary), most commonly rheumatoid arthritis or lupus. If you have persistent, severe dryness in both your eyes and mouth that doesn’t respond to typical remedies, Sjögren’s is one of the conditions your doctor would want to rule out.
Contact Lens Wear
Contact lenses sit directly in the tear film, splitting it into a thin layer above the lens and another below it. This disrupts the oil layer’s ability to spread evenly and accelerates evaporation. Over time, lens wear also reduces the mucin coating on the cornea’s surface, a protective barrier that helps tears spread smoothly and minimizes friction during blinking. Without adequate mucin, each blink creates more mechanical friction between the lens, the eyelid, and the eye surface. This friction can cause changes in the cells lining the inner eyelid and the conjunctiva, driving a cycle of inflammation and discomfort that makes the dryness progressively harder to ignore.
LASIK and Eye Surgery
Dry eye is the most common side effect after LASIK. Roughly 95% of patients experience some dryness immediately after surgery, and about 60% still report symptoms a month later. The primary cause is nerve damage. During LASIK, creating the corneal flap and reshaping the underlying tissue severs sensory nerve fibers in the cornea. Those nerves normally trigger both your blink reflex and your baseline tear production. With the nerve signals disrupted, you blink less often and produce fewer tears. For most people, the nerves gradually regenerate over several months to a year, and dryness improves. For a smaller percentage, symptoms become chronic.
Vitamin A Deficiency
Vitamin A is essential for maintaining the mucous membranes of the eye. When levels are severely low, the conjunctiva (the clear tissue covering the white of the eye) loses its ability to produce mucus and begins behaving more like skin, producing a tough protein called keratin instead. The glands embedded in the conjunctiva stop functioning normally, leading to a loss of both the watery and mucous components of the tear film. While this level of deficiency is uncommon in developed countries, it remains a leading cause of preventable eye damage globally and can occur in people with malabsorption conditions, very restrictive diets, or chronic liver disease.
Age
Tear production naturally declines with age. The lacrimal glands produce less fluid, the meibomian glands become less active, and the composition of the tear film shifts. By the time most people reach their 50s and 60s, some degree of tear film instability is common. This age-related decline doesn’t happen in isolation. It compounds the effects of everything else on this list: medications become more numerous, hormonal changes have taken hold, and cumulative screen exposure adds up. That layering of causes is why dry eye tends to become more persistent and harder to manage with age rather than less.