Dry eye can occur when tears have too little water or oil.

Dry eye, also known as dry eye syndrome, is a condition that occurs when the eyes don’t produce enough tears or when the tears evaporate too quickly. This leads to insufficient moisture and lubrication on the surface of the eyes.

Dry eye can lead to significant discomfort, such as causing a gritty or burning sensation, redness, or sensitivity to light. It can also cause blurred vision, eye fatigue, and difficulty reading or doing other visually intense activities.

Dry eye syndrome can be classified into two main categories: evaporative dry eye and aqueous-deficient dry eye.

Evaporative dry eye

Evaporative dry eye occurs when the oily layer of tears, which helps prevent their evaporation, is deficient or of poor quality.

It can develop from dysfunction of the meibomian gland, which is the small oil-producing gland of the eyelid. Other causes include inflammation of the eyelids and environmental factors, such as low humidity or prolonged use of computer screens.

Aqueous-deficient dry eye

Aqueous-deficient dry eye occurs when the lacrimal glands, which produce tears, fail to produce enough of the watery component of tears, known as the aqueous layer.

Autoimmune diseases, hormonal changes, certain medications, and aging can cause it.

The most common type of dry eye is evaporative dry eye. According to a 2018 paper, it occurs in over 85% of dry eye cases.

How do I know what type of dry eye I have?

The best way to determine the type of dry eye you have is to visit an eye doctor or ophthalmologist for an eye exam.

During the exam, the doctor will perform a series of tests to evaluate your tear production, tear quality, and the overall health of your eyes.

These tests may include the following:

  • Evaluation of the meibomian glands: Doctors can assess the meibomian glands to check for dry eye. They may use special instruments to directly see the glands or take pictures (meibography) to evaluate their health and function.
  • Schirmer’s test: A Schirmer’s test involves placing a small strip of filter paper, known as a Schirmer strip, in the lower eyelid for about 5 minutes to determine the amount of tear production. A result under 5 millimeters may indicate aqueous-deficient dry eye.
  • Tear breakup time (TBUT) test: The TBUT test primarily evaluates evaporative dry eye by assessing the stability of the tear film on the eye’s surface. The test involves placing a dye on the eye and observing how long it takes for dry spots or disruptions to appear. These can indicate insufficient tear production and contribute to dry eye symptoms.
  • Ocular surface staining: Ocular surface staining uses a dye to assess the condition of the cells on the surface of the eye. By detecting areas of staining, it helps identify any damage or inflammation in the eye.

Based on the results of these tests, your doctor can determine the type and severity of your dry eye and develop an appropriate treatment plan.

Several medical conditions can cause dry eye, including:

  • Diabetes: High blood sugar levels can damage the nerves and blood vessels in the eye, leading to dry eye. According to a 2016 review, 54% of people with diabetes have dry eye.
  • Sjogren’s disease: Sjogren’s disease is an autoimmune disorder that causes inflammation in the body’s moisture-producing glands, including the tear glands.
  • Rheumatoid arthritis (RA): RA is an autoimmune disorder that can cause inflammation in various parts of the body, including the tear glands.
  • Lupus: Lupus is another autoimmune disorder that can cause dry eye due to inflammation.
  • Thyroid disorders: An overactive or underactive thyroid gland can cause dry eye symptoms.
  • Rosacea: Rosacea is a chronic inflammatory condition that can affect the eyes and cause dry eye symptoms.
  • Allergies: Seasonal or year-round allergies can cause eye inflammation and dry eye symptoms.
  • Vitamin A deficiency: A lack of vitamin A can lead to dry eye.
  • LASIK surgery: Dry eyes are a very common side effect of LASIK surgery.

Treatment for dry eye may depend on the underlying cause and severity of the condition. Here are some common treatments:

  • Artificial tears: These over-the-counter eye drops can help lubricate and moisturize the eyes.
  • Prescription eye drops: For more severe cases of dry eye, your eye doctor may recommend prescription eye drops, such as Restasis or Xiidra.
  • Warm compresses: Applying a warm compress to the eyes can help stimulate the production of natural oils in the eyes, which can help reduce dryness.
  • Eyelid hygiene: Keeping the eyelids clean and free of debris can help prevent clogging of the meibomian glands, which can contribute to dry eye.
  • Omega-3 supplements: Taking omega-3 supplements can help promote eye health.
  • Environmental changes: Changing your environment when possible, such as using a humidifier or avoiding exposure to dry or windy conditions, can also help reduce symptoms of dry eye.

Artificial tears and prescription dry eye medications are typically more helpful for aqueous-deficient dry eye. Warm compresses and eyelid hygiene are typically more helpful for evaporative dry eye.

Dry eye syndrome can significantly affect your quality of life. It can cause blurred vision, redness, and a gritty or burning sensation in the eyes.

Dry eye can be classified into two main categories: aqueous-deficient dry eye and evaporative dry eye. Aqueous-deficient dry eye is the failure to produce enough of the watery component of tears. Evaporative dry eye is the failure to produce enough oil so tears don’t evaporate.

If you suspect you may have dry eye, consider reaching out to an eye care professional, such as an optometrist or ophthalmologist. They can evaluate your symptoms, perform necessary tests, and provide an accurate diagnosis.