Dry eye has a recognizable pattern: a stinging, burning, or scratchy feeling in both eyes, often worse at the end of the day or after long stretches of screen time. If your eyes feel gritty, look red, blur when you read, or (counterintuitively) water constantly, those are all classic signs. The tricky part is that several other conditions overlap with dry eye, so knowing what to look for helps you figure out whether that’s really what’s going on.
The Core Symptoms to Check For
Dry eye typically affects both eyes at once and produces a combination of sensations rather than a single symptom. The most common ones are:
- Burning, stinging, or scratchiness that worsens through the day
- A gritty feeling, like sand or something stuck in your eye
- Excessive tearing, which is your eyes’ reflex response to irritation
- Blurred vision that comes and goes, especially during reading or driving
- Sensitivity to light
- Eye redness
- Stringy mucus in or around the eyes
- Difficulty wearing contact lenses comfortably
The watery-eyes symptom confuses a lot of people. It seems like the opposite of “dry,” but what’s happening is that irritation triggers a flood of low-quality, watery tears that don’t actually protect the eye surface the way a healthy tear film does. If your eyes water constantly yet still feel uncomfortable, dry eye is a likely explanation.
A Quick Self-Assessment You Can Do Now
Eye doctors often use a standardized questionnaire called the OSDI (Ocular Surface Disease Index) to gauge dry eye severity. It asks 12 questions across three categories: how your eyes feel, how your vision functions during tasks like reading or driving, and whether certain environments (wind, air conditioning, low humidity) trigger your symptoms. Each question is scored from 0 (never) to 4 (always), and the final score lands on a scale of 0 to 100.
You can find the OSDI online and score yourself at home. A score under 13 is considered normal. Scores of 13 to 22 suggest mild dry eye, 23 to 32 is moderate, and anything above 32 indicates severe symptoms. It’s not a diagnosis on its own, but it gives you a useful starting point and something concrete to share with an eye doctor if you decide to go.
Why Screen Time Makes It Worse
If you notice your symptoms flare up after hours on a computer or phone, there’s a direct physiological reason. Your blink rate drops dramatically during screen use. Under normal conditions, you blink roughly 18 to 22 times per minute. During focused computer work, that can fall to as few as 3 to 7 blinks per minute. Each blink spreads a fresh layer of tears across your eye surface, so fewer blinks mean faster evaporation and more irritation.
Incomplete blinks matter too. When you’re concentrating, your upper eyelid often doesn’t travel all the way down to cover the cornea. Even if you blink at a reasonable rate, those partial blinks leave the lower portion of your eye exposed. This is one reason why dry eye symptoms tend to build over the course of a workday and feel better in the morning after a night of closed-eye rest.
What’s Actually Happening in Your Tear Film
Your tears aren’t just saltwater. They’re a three-layered film: an oily outer layer that prevents evaporation, a watery middle layer that hydrates and nourishes, and a mucus layer that helps tears stick to the eye surface. Dry eye happens when something goes wrong with one or more of these layers, and the type matters because it points to different causes.
Over 85% of dry eye cases are the evaporative type, where the oily outer layer is deficient. This is caused by dysfunction in the meibomian glands, tiny oil-producing glands along your eyelid margins. When these glands clog or stop working properly, tears evaporate too quickly. Only about 10% of cases are the aqueous-deficient type, where your tear glands simply don’t produce enough of the watery component. Many people have a mix of both.
Knowing which type you have changes what treatments work best, which is one reason a professional evaluation is more useful than guessing at home.
Risk Factors That Make Dry Eye More Likely
Certain medications are well-known triggers. Isotretinoin (commonly prescribed for acne) can damage the meibomian glands. Antihistamines, which many people take daily for allergies, reduce tear production as a side effect. Glaucoma eye drops used long-term frequently cause dry eye because of preservatives in the drops. Statins, some antidepressants, and several cancer treatments are also linked to dry eye symptoms.
Beyond medications, the biggest demographic risk factors are age and sex. Dry eye becomes more common after 50 and is roughly twice as prevalent in women, partly due to hormonal changes during menopause. People with autoimmune conditions like lupus or rheumatoid arthritis are also at higher risk because these diseases can attack the tear-producing glands directly.
Environmental factors play a significant role too. Dry climates, air conditioning, forced-air heating, airplane cabins, and ceiling fans all accelerate tear evaporation. If your symptoms are clearly seasonal or location-dependent, your environment may be the primary driver.
Dry Eye vs. Allergies: How to Tell the Difference
This distinction trips people up because the two conditions frequently overlap. Research on nearly 700 patients found that 45% of people with dry eyes also had significant itching (the hallmark of allergies), and 58% of people with itchy eyes also had clinically significant dryness. So having both at once is common, not unusual.
The best way to separate them: itching is the defining symptom of allergic eye disease. If your primary complaint is intense itchiness, especially with swollen eyelids or a seasonal pattern, allergies are likely in the mix. Dry eye, by contrast, leans more toward burning, stinging, and grittiness. Redness shows up in both conditions. If you have burning plus itching plus redness, you may genuinely have both problems at the same time, which an eye doctor can sort out.
What Happens at a Professional Eye Exam
If you suspect dry eye, an optometrist or ophthalmologist can run a few straightforward tests to confirm it and determine the type.
The tear breakup time test measures how quickly your tear film deteriorates after a blink. The doctor places a drop of fluorescein dye in your eye and watches under a blue light. In healthy eyes, the tear film stays intact for about 10 seconds. If dry spots appear in 5 seconds or less, that’s considered abnormal and suggests your tears are evaporating too fast.
The Schirmer test measures tear production volume. A small strip of filter paper is placed on your lower eyelid, you close your eyes for five minutes, and the doctor measures how much of the strip got wet. Less than 5 millimeters of wetting suggests your eyes aren’t producing enough tears.
Some clinics also measure tear osmolarity, which is essentially how concentrated your tears are. Healthy tears measure around 302 milliosmoles per liter. Mild to moderate dry eye pushes that to around 315, and severe cases average 336. Higher concentration means less water in the tear film, which causes more irritation to the eye surface.
These tests are painless and take only a few minutes. Together, they tell your doctor whether you have dry eye, how severe it is, and whether the problem is primarily evaporative or aqueous-deficient.
What Happens If You Ignore It
Mild dry eye is uncomfortable but manageable. Left untreated over time, though, it can cause real damage. A compromised tear film leaves the cornea vulnerable. Dust and small particles can scratch the surface more easily. Bacteria that healthy tears would normally wash away can take hold, leading to infections like keratitis (corneal inflammation) that, in serious cases, causes permanent scarring and vision loss.
Chronic dry eye can also lead to corneal ulcers, which are open sores on the eye’s surface. These are painful, can spread, and require prompt treatment to prevent lasting damage. On the more everyday end, untreated dry eye makes contact lenses intolerable, progressively blurs your vision during tasks like reading and driving, and can cause enough light sensitivity that keeping your eyes open in bright environments becomes difficult.
None of this is meant to be alarming. Most people with dry eye manage it successfully with over-the-counter artificial tears, warm compresses, environmental adjustments, or prescription options if needed. The point is that “just dry eyes” is worth addressing rather than powering through indefinitely.