Dry Eyes: Symptoms and Causes of Dry Eye Syndrome

In the evening your eyes sting as if a grain of sand has gotten under the eyelid, and you don't want to go back to the screen at all. This is often what dry eyes look like — a common condition that is usually not dangerous but really ruins the workday.

What dry eyes and dry eye syndrome are

The tear film moisturizes the eye, washes away dust, and affects the clarity of vision. When the eye cannot maintain a healthy coating of tears — too few tears are produced or they evaporate too quickly — dryness appears. Doctors call this condition dry eye syndrome, or keratoconjunctivitis sicca.

Numbers: dry eye syndrome affects 5–6% of the population; among people over 40 the frequency rises to 12–22%, and among the elderly — up to 34%. For most people it is only discomfort without vision loss, but in severe cases the cornea can be damaged or become infected.

Symptoms of dry eye

The typical picture: dryness, burning, irritation, and a gritty sensation. Added to these are itching, scratching, a feeling of eye fatigue, pain, redness, tightness, pressure behind the eye, and sensitivity to bright light. Usually both eyes are affected, and the discomfort increases over the course of the day.

A quick self-check that diagnoses nothing but helps describe the picture to a doctor: see whether the discomfort worsens toward evening, whether it appears in an office under air conditioning, whether it subsides in the shower or in foggy weather, and whether there is a sensation of a speck in a clean eye.

Symptoms worsen where there is less blinking and drier air:

• reading, computer, driving, TV — anything that keeps the gaze fixed for a long time;
• wind, dust, smoke, including cigarette smoke;
• air conditioning, heater, fan, dry rooms, high altitudes, and airplanes;
• days with low humidity.

Relief usually comes in cold, rainy, or foggy weather and in humid rooms.

Causes of dry eyes

The cause is always one of two: too few tears or they dry out too quickly. Beyond that are factors that increase the likelihood: age over 50, contact lenses, long screen work without breaks, air-conditioned and heated rooms, wind, dryness and dust, smoking, and alcohol.

The list also includes some medications — certain antidepressants, blood pressure drugs, cold and allergy medicines. Diseases can also cause dryness: blepharitis, meibomian gland dysfunction, Sjögren's syndrome, lupus, rheumatoid arthritis. Less commonly — burns, previous eye surgeries, and sarcoidosis. About half of people who wear contact lenses complain of dryness, and diabetics are at risk.

Why eyes can be dry and yet watery

It looks paradoxical: a person comes with the complaint "my eyes are dry and watery." The mechanics are simple. An irritated eye triggers reflex tearing — as if something has gotten into it. But these are watery-type tears, produced in response to damage, irritation, or emotion. They lack the lubricating properties needed to protect the surface, so it doesn't get better.

Dry eyes with allergies and with age

Allergy and cold medicines belong to the agents that can cause dry eyes or worsen them. Age-related dry eyes are a separate story. Over the years tear production decreases; in postmenopausal women hormonal changes are added: the meibomian glands stop working properly, and the tear becomes inadequate. Most often, reduced tear production occurs after age 60.

How it is diagnosed and when to see a doctor

At an appointment, visual acuity is checked, the eye is examined with a slit lamp, the cornea and tear film are stained, the tear film breakup time and tear production rate (Schirmer's test) and tear concentration are measured. Assessment of symptoms is also part of diagnosis — questionnaires exist, for example McMonnies and Ho.

See a doctor: if dryness does not resolve within a few weeks, if the shape of the eyelid has changed, if the eye is red and painful, crusts, discharge, or an ulcer have appeared, if there was an injury, if the eye is bulging or the eyelid has drooped. A separate reason — dry eyes together with joint pain or stiffness and dry mouth.

Dry eyes on their own are not a reason to call an ambulance; 103 or 112 — if vision has changed abruptly (wavy lines, flashes, vision loss), it is painful to look at light, the eye is very dark red, there was an injury or a foreign body is stuck in the eye, and also with a red eye accompanied by severe headache and nausea.

This material is for reference: it helps to recognize the condition "on sight," but does not replace a doctor's consultation — the causes and management are determined by an ophthalmologist at an appointment.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer