Dry eyes can be a symptom of dozens of underlying conditions, from autoimmune diseases and hormonal shifts to medication side effects and nutritional deficiencies. While occasional dryness is common (affecting roughly 35% of people worldwide), persistent dry eyes often signal something specific happening in your body that’s worth identifying. The cause determines the fix, so understanding what’s behind your symptoms matters more than just treating the surface irritation.
Autoimmune and Inflammatory Diseases
The most well-known systemic cause of dry eyes is Sjögren’s syndrome, a chronic autoimmune condition in which the immune system mistakenly attacks the glands that produce moisture in the eyes and mouth. People with Sjögren’s typically experience both dry eyes and a dry mouth together, and it frequently occurs alongside other autoimmune conditions like rheumatoid arthritis and lupus.
Rheumatoid arthritis, lupus, scleroderma, and sarcoidosis can all produce dry eyes through chronic inflammation that damages tear-producing tissue. If your dry eyes come with joint pain, skin changes, persistent fatigue, or a dry mouth, that combination points toward an autoimmune process rather than a simple environmental cause.
Diabetes and Blood Sugar Problems
Chronically elevated blood sugar damages the eyes in ways that go beyond the well-known risk of diabetic retinopathy. High glucose levels cause nerve fiber loss in the cornea and impair the glands responsible for both the watery and oily components of your tears. Sugar buildup inside cells creates osmotic stress that leads to swelling and glandular dysfunction, reducing tear output. Diabetes also damages the mucus-producing cells on the eye’s surface, which further destabilizes the tear film. If you have diabetes and notice worsening dry eyes, it may reflect how well your blood sugar has been controlled over time.
Hormonal Changes and Menopause
Hormonal shifts are one of the most common reasons dry eyes disproportionately affect women. Globally, about 39% of women experience dry eye compared to 31% of men, and much of that gap traces back to sex hormones. Androgens play a surprisingly important role in eye health: they regulate the oil-producing glands along your eyelid margins and support the tear glands directly. When androgen levels drop, the oil composition in your eyelids changes. Free fatty acids increase, forming irritating foam-like secretions that build up along the eyelid and trigger surface inflammation.
Menopause and perimenopause bring a decline in both androgens and estrogen. The effect of estrogen on dry eye is complicated. It can actually block androgen receptors and interfere with oil production in the eyelids, which is why hormone replacement therapy sometimes makes dry eyes worse rather than better. This is one reason dry eye often worsens during midlife even when other aspects of health are stable.
Medications That Reduce Tear Production
A long list of common medications cause or worsen dry eyes, and many people don’t connect the two. The major categories include:
- Antihistamines (allergy medications) reduce the watery component of tears
- Antidepressants, including SSRIs, SNRIs, and tricyclics, all interfere with tear production through their effects on nerve signaling
- Blood pressure medications, particularly beta blockers, reduce tear output, while diuretics decrease fluid availability throughout the body
- Pain relievers like aspirin and ibuprofen are secreted into your tears, where they increase evaporation and destabilize the tear film
- Acne medications containing isotretinoin cause programmed cell death in oil-producing glands, disrupting the eyelid’s oil layer
- Decongestants constrict blood vessels supplying the tear system, cutting off the raw materials for tear production
If your dry eyes started or worsened around the time you began a new medication, that timing is worth noting. Even over-the-counter allergy pills taken daily can be enough to tip the balance.
Screen Time and Reduced Blinking
You normally blink about 15 times per minute. During screen use, that drops to 5 to 7 times per minute. Since blinking is the mechanism that spreads moisture across the eye’s surface, cutting your blink rate by more than half leaves the tear film exposed and evaporating far faster than it’s replenished. This isn’t a disease, but for many people it’s the primary driver of daily dryness. The effect compounds over hours, which is why symptoms tend to peak in the late afternoon or evening after a full workday at a computer.
Eyelid Gland Problems and Rosacea
The oil glands lining your upper and lower eyelids (meibomian glands) produce the lipid layer that prevents your tears from evaporating too quickly. When these glands become blocked or dysfunctional, the result is evaporative dry eye, the most common subtype. You may notice your eyes feel worse in wind or air conditioning, or that tears actually run down your cheeks even though your eyes feel dry, because the watery layer is being produced but evaporating immediately without its protective oil coating.
Ocular rosacea is closely tied to this type of gland dysfunction. It can occur alongside skin rosacea (facial redness, flushing, visible blood vessels) or entirely on its own. The eyelids may look red or swollen along the margins, and the eyes themselves burn or sting.
Vitamin A Deficiency
Vitamin A is essential for maintaining the surface cells of the eye. Without it, the conjunctiva and cornea undergo a process where normal moist tissue transforms into dry, thickened, keratinized tissue. Early signs include difficulty seeing at night and general eye dryness. If caught early, high-dose vitamin A supplementation can reverse these changes within about two months. Left untreated, the dryness can progress to corneal ulcers, scarring, and permanent vision loss. While severe deficiency is rare in high-income countries, it remains a leading cause of preventable blindness globally and can occur in people with conditions that impair fat absorption, since vitamin A is fat-soluble.
Thyroid Disorders
Thyroid disease, particularly an overactive thyroid associated with Graves’ disease, can cause dry eyes through a combination of inflammation around the eye socket, incomplete eyelid closure, and increased surface exposure. Even people with underactive thyroid conditions report higher rates of dry eye. The Mayo Clinic lists thyroid disorders among the recognized medical causes of decreased tear production.
Neurological Conditions
Any condition that reduces your ability to blink fully can lead to dry eyes through corneal exposure. Bell’s palsy, which temporarily paralyzes one side of the face, is a classic example. When the eyelid can’t close completely, the cornea dries out and becomes inflamed. Parkinson’s disease reduces blink rate and blink completeness, producing a similar effect over time. The resulting dryness and inflammation can actually alter the blink reflex further, creating a cycle where nerve damage leads to dryness, and dryness leads to abnormal blinking patterns.
Signs Your Dry Eyes Point to Something Bigger
Simple dry eye from screen use or a dry environment tends to be mild, intermittent, and responsive to lubricating drops. The pattern that suggests a systemic cause looks different. Dry mouth accompanying dry eyes points toward Sjögren’s syndrome. Joint pain or swelling alongside eye symptoms raises the possibility of rheumatoid arthritis or lupus. Dry eyes that started with a new medication have an obvious timeline to investigate. Worsening dryness during perimenopause or after changes in hormonal therapy suggests a hormonal driver.
Persistent, worsening dry eyes that don’t respond to basic measures like artificial tears and screen breaks deserve investigation beyond the surface. Identifying the underlying cause often matters more than any eye drop, because treating the root condition can resolve the eye symptoms along with it.