Your eyes may feel scratchy by mid-afternoon, water unexpectedly outdoors, or become uncomfortable every time you sit down at a screen. If you are wondering what causes dry eyes, the answer is rarely just one thing. Dry eye symptoms often develop when everyday habits, the environment and changes within the eye all place extra strain on the tear film.
Dry eye is very common, but it should not simply be accepted as part of getting older or working at a computer. Understanding the cause gives us a much better chance of finding advice and treatment that suits your eyes, your routine and, where relevant, your contact lenses.
What causes dry eyes?
Healthy tears do much more than make the eye feel wet. They form a smooth protective layer over the front surface of the eye, helping maintain clear vision, comfort and protection from irritation. This tear film has several parts: an oily outer layer that slows evaporation, a watery layer that provides moisture, and a mucus layer that helps tears spread evenly.
Dry eye can occur when the eyes do not produce enough tears, when tears evaporate too quickly, or when the tear film is unstable. Many people have a mixture of these issues. That is why one person may mainly notice burning and grit, while another experiences fluctuating blur, watering or tired-feeling eyes.
Meibomian gland blockage and fast-evaporating tears
Along the edge of each eyelid are tiny meibomian glands. They produce the oil that sits on the outer layer of your tears. When these glands become blocked or are not working well, tears can evaporate too quickly. This is one of the most frequent causes of dry eye discomfort.
The eyelids may look normal, or there may be crusting, redness around the lid margins or a history of styes. Blepharitis, an inflammation around the eyelids, often occurs alongside meibomian gland problems. Gentle, regular lid care can be useful, but the most appropriate approach depends on the condition of your lids and the severity of your symptoms.
Age, hormones and natural changes
Tear production and tear quality can change over time. Dry eye becomes more common with age, partly because the glands that support the tear film may become less effective. Hormonal changes can also play a part, which is why symptoms are often reported around the menopause.
This does not mean dry eyes are inevitable, nor that everyone needs the same treatment. A careful assessment can distinguish occasional irritation from a persistent tear-film problem that needs more structured support.
Screens, reading and concentrated work
People often blame the screen itself, but the bigger issue is how we use it. When concentrating on a laptop, phone, book or detailed task, we tend to blink less often and less completely. Incomplete blinks do not spread the oily layer of the tear film properly, leaving moisture to evaporate.
Long working days, driving, gaming and evening scrolling can all contribute. Symptoms may be most noticeable late in the day, especially in heated offices or rooms with air conditioning. Taking regular visual breaks, looking into the distance and making a conscious effort to blink fully can help. Positioning a screen slightly below eye level may also reduce how widely the eyes are held open.
Screen-related dry eye can improve with these practical adjustments, but persistent discomfort is worth checking. It may reveal an underlying lid-gland issue that a screen-heavy routine has brought to the surface.
Your environment can make symptoms worse
Wind, cold weather, central heating, air conditioning and car fans can all dry the surface of the eye. A day spent outdoors, particularly while cycling or walking in windy conditions, may leave eyes sore even if they felt fine in the morning.
Smoke and airborne irritants can have a similar effect. Hay fever may complicate matters further. Allergy can make eyes itchy, watery and red, while rubbing them can worsen irritation. It is possible to have both allergy and dry eye at the same time, so choosing drops without advice is not always straightforward.
Even watering can be a dry-eye symptom. If the eye surface becomes irritated, it can trigger a reflex flow of watery tears. These tears do not necessarily contain the balanced oil and mucus needed to keep the eye comfortable for long, so the cycle of watering and dryness continues.
Contact lenses and dry eye symptoms
Contact lenses are a convenient and flexible way to see clearly, but they can make existing dryness more noticeable. A lens sits on the tear film, and if that film is poor in quality, the lens may feel dry, move uncomfortably or become harder to wear as the day goes on.
Lens material, replacement schedule, cleaning routine and wearing time all matter. So does your prescription and the health of the front surface of your eye. It is not always necessary to stop wearing contact lenses permanently. Sometimes a change in lens type, wear pattern or care routine makes a meaningful difference. In other cases, treating the dry eye first is the sensible next step.
Do not try to push through significant discomfort, redness or reduced wearing time. Contact lens discomfort deserves individual advice, particularly if symptoms are new or getting worse.
Medicines and health conditions
Some medicines can reduce tear production or affect the tear film. These may include certain antihistamines, antidepressants, blood pressure medicines, decongestants and acne treatments. This does not mean you should stop a prescribed medicine. Instead, mention it at your eye examination or dry eye appointment so it can be considered as part of the wider picture.
Dry eye may also be associated with conditions that affect the skin, eyelids or immune system. Rosacea, for example, can be linked with meibomian gland dysfunction. Thyroid problems, diabetes, arthritis and autoimmune conditions may also be relevant for some people.
A change in general health is only one possible factor, and dry eye does not automatically indicate a serious condition. However, your optometrist should know about your medical history, medication and any recent changes in symptoms. Good eye care starts with seeing the whole person, not just a red or watery eye.
Everyday habits that can contribute
Dry eye can be influenced by sleep, hydration, diet and how consistently we care for our eyelids. Poor sleep may leave eyes feeling more tired and uncomfortable, while eye make-up or skin products that collect near the lid margins can contribute to irritation in some people.
Not every dry eye problem is solved by drinking more water, despite the popularity of that advice. Staying well hydrated is sensible for general health, but it will not unblock meibomian glands or correct every form of tear-film instability. Similarly, lubricating drops can be very helpful, but the best type and frequency depend on why your eyes are dry. Some people need a simple preservative-free lubricant; others need a more targeted plan that includes lid treatment or changes to their environment.
When should you arrange an eye assessment?
Occasional dryness after a long day may settle with rest and a few practical changes. If symptoms are frequent, affect your work or driving, limit contact lens wear, or leave your vision intermittently blurred, it is a good idea to arrange an assessment.
An optometrist can examine the eyelids, tear film and surface of the eye, as well as check whether your prescription or contact lenses are contributing. At Mark Darling Eyecare & Opticians, we take time to understand when symptoms occur and what is making them worse, rather than offering a one-size-fits-all answer.
Seek urgent advice if you have severe pain, a sudden change in vision, marked light sensitivity, a red eye that is getting worse, an eye injury, or symptoms while wearing contact lenses that do not settle after removing them. These signs are not typical dry eye symptoms to manage alone.
Dry eyes can be frustrating, particularly when they interfere with work, hobbies or the simple comfort of seeing clearly. With the right assessment, small changes and the appropriate care, many people find their eyes feel more comfortable and dependable again.