What Is Dry Eye Syndrome?

Dry Eye Syndrome (DES) — also known as keratoconjunctivitis sicca — is a chronic condition in which the eyes either do not produce enough tears or produce tears that evaporate too quickly. The result is an unstable tear film that fails to keep the ocular surface properly lubricated, leading to discomfort and, in some cases, damage to the surface of the eye.

Despite its name, dry eye doesn't always mean simply "not enough" tears. Many people with the condition actually have excessive watery tears as a reflex response — but these tears are of poor quality and don't provide lasting relief.

How Common Is Dry Eye?

Dry eye is one of the most prevalent eye conditions seen in eye care clinics worldwide. It is more common in older adults and in women, particularly following hormonal changes associated with menopause. Increased screen time and the widespread use of air conditioning have also contributed to its growing prevalence in younger populations.

The Two Main Types of Dry Eye

Aqueous Deficient Dry Eye (ADDE)

This occurs when the lacrimal glands don't produce enough of the watery component of tears. It can be associated with conditions such as Sjögren's syndrome, an autoimmune disease that attacks tear and saliva glands.

Evaporative Dry Eye (EDE)

This is the most common type, accounting for the majority of dry eye cases. Here, the volume of tears is adequate, but they evaporate too quickly — usually because of a deficient lipid (oily) layer. Meibomian gland dysfunction (MGD), where the glands in the eyelids that produce the oily layer become blocked or dysfunctional, is the leading cause.

Risk Factors and Causes

  • Age — tear production naturally decreases with age
  • Gender — hormonal differences make women more susceptible
  • Screen use — reduced blinking rate during screen use increases evaporation
  • Environment — air conditioning, heating, wind, and low humidity
  • Contact lens wear — lenses can disrupt the tear film
  • Medications — antihistamines, antidepressants, diuretics, and beta-blockers can reduce tear production
  • Refractive surgery — procedures like LASIK can temporarily disrupt tear production
  • Systemic diseases — rheumatoid arthritis, lupus, Sjögren's syndrome, thyroid disorders
  • Vitamin A deficiency

Symptoms of Dry Eye Syndrome

Symptoms can vary in severity and may worsen throughout the day or in certain environments:

  • Persistent dryness or scratchiness
  • Stinging or burning sensation
  • Stringy mucus in or around the eye
  • Sensitivity to light
  • Redness
  • Blurred vision that fluctuates — often temporarily improving with blinking
  • Eye fatigue, especially during prolonged reading or screen use
  • Difficulty wearing contact lenses
  • Paradoxically, excessive tearing

Diagnosis: What to Expect

An eye care professional will assess dry eye using several tests, which may include:

  1. Slit-lamp examination — to view the tear film and ocular surface
  2. Schirmer's test — measures tear production volume
  3. Tear break-up time (TBUT) — measures how quickly the tear film breaks down
  4. Osmolarity testing — assesses tear film concentration
  5. Meibography — imaging of meibomian glands

Management Options

Lifestyle Adjustments

  • Follow the 20-20-20 rule during screen use: every 20 minutes, look at something 20 feet away for 20 seconds
  • Consciously blink more during screen use
  • Use a humidifier in dry environments
  • Stay well hydrated
  • Eat a diet rich in omega-3 fatty acids (oily fish, flaxseed)

Warm Compresses & Lid Hygiene

For meibomian gland dysfunction, applying a warm compress to closed eyelids for 10 minutes daily and gently massaging the lids can help liquefy and release the blocked oils.

Artificial Tears & Lubricating Drops

The first-line treatment for most dry eye. Preservative-free formulations are recommended for frequent use. Sodium hyaluronate-based drops are particularly well-regarded for their ability to retain moisture.

Prescription Treatments

For moderate to severe cases, doctors may prescribe anti-inflammatory eye drops, cyclosporine-based treatments, or lifitegrast to address the underlying inflammation that drives many cases of chronic dry eye.

Procedures

Punctal plugs (tiny silicone inserts placed in the tear drainage ducts) help retain tears on the eye surface. Intense pulsed light (IPL) therapy is an emerging option for meibomian gland dysfunction.