Dry eye, also known as dry eye syndrome or dry eye disease, is a condition that occurs when your eyes do not produce enough quality tears to keep the eye surface properly lubricated. This can result in symptoms like burning, itchiness, redness, and general discomfort.

If you notice any changes in vision or experience symptoms of dry eye, it’s recommended to seek testing from an eye care professional. An optometrist or ophthalmologist can determine the cause of your symptoms and provide a diagnosis.

There is no single test to diagnose dry eye. Instead, eye care providers rely on a combination of questionnaires and clinical exams to evaluate tear quantity and quality, the condition of the eyelids, and the health of the tear film. Early diagnosis is important, as untreated dry eye may lead to infections or vision complications.

Questionnaire

One of the first steps in diagnosing dry eye is a verbal questionnaire about your symptoms. Providers may ask which symptoms you’re experiencing, how long they’ve lasted, and their effect on daily activities.

A widely used tool is the Ocular Surface Disease Index (OSDI), which consists of 12 questions that assess:

  • your symptoms (such as blurry vision or discomfort)

  • difficulty with tasks (like reading or night driving)

  • environmental triggers (like dry or windy conditions)

You may also be asked about lifestyle habits and medical history to give your provider a better understanding of potential underlying causes. If diagnosed with dry eye, these questionnaires may be repeated during follow-up visits to monitor treatment progress.

Comprehensive Eye Exam

After reviewing your symptoms, your provider may perform a comprehensive eye exam. This may involve pupil dilation using eye drops to allow more light into the eye for better examination.

Several tests are typically conducted:

Slit Lamp Test

This test uses a slit lamp microscope to examine both the front and back parts of the eye. A beam of light is directed into the eye while the provider evaluates the health and moisture levels of the tear film.

The test can identify:

  • corneal damage or swelling

  • tear production levels

  • swelling or irritation of the eyelids

  • issues with blinking

  • imbalances in water, oil, or mucus components of the tear film

Schirmer’s Test

This test measures tear production. During the procedure:

  • small paper strips are placed under each lower eyelid

  • numbing drops are used to reduce irritation

  • you’ll be asked to close your eyes for five minutes

  • the strips are removed and examined for moisture

If your tears wet less than five millimeters of the strip, it may indicate dry eye. Some providers may use a thread-based variation called the phenol red test.

Tear Break Up Time (TBUT) Test

This test assesses how quickly tears evaporate. During the exam:

  • colored dye is added to your eye

  • you’re instructed to blink until the dye spreads

  • you hold your eyes open while the provider measures how long the dye remains

If the dye breaks up in less than five seconds, dry eye may be present.

Other Exams

Additional tests may help confirm the diagnosis:

  • fluorescein staining: checks for scratches or damage to the cornea

  • lissamine green staining: evaluates inflammation and tear film quality

  • tear film osmolarity: analyzes tear salt concentration, which can be higher in dry eye cases

Screening for Related Conditions

Dry eye symptoms can resemble those of other eye conditions. Your provider may perform screenings to rule out the following:

Condition Screening Method
Viral conjunctivitis Questions about recent illness or contact with sick individuals; lymph node check
Blepharitis Eyelid exam using magnification; skin sampling for parasites
Keratitis History of injury or contact lens use; slit lamp test for corneal damage
Eye infection Eye exam to detect bacteria, fungi, viruses, or irritants

Dry eye can also occur with other medical conditions such as:

  • Sjögren’s syndrome: causes dry eyes and mouth

  • Rheumatoid arthritis: autoimmune inflammation of joints

  • Lupus: inflammatory condition affecting healthy tissues

  • Diabetes (Type 1 & 2): impacts blood sugar and eye health

  • Scleroderma: causes skin thickening

  • Dermatomyositis: leads to muscle weakness and skin rash

If another health issue is suspected, you may be referred to a specialist for further testing.

A Quick Review

Dry eye is a common condition that affects tear quality and quantity, leading to symptoms like irritation, redness, and blurry vision. Diagnosis usually involves a verbal questionnaire and comprehensive eye exam.

Further tests may assess tear production, evaporation rate, and corneal health. Identifying and treating dry eye early can improve comfort and prevent complications. If necessary, providers may screen for related eye or autoimmune conditions and refer you to other specialists for full evaluation.