How Does My Optometrist Know If I Have Dry Eyes? 👁️

Hello and welcome! As an experienced optometrist, I’m here to explain how we diagnose dry eyes through a variety of tests. Understanding these procedures can ease your concerns and help you know what to expect during your exam.

Tests for Tear Volume

• Schirmer's Test:
  A paper strip is placed under the lower eyelid to measure how much tears are produced in five minutes. This helps us determine if your tear volume is sufficient. 😊
• Phenol Red Thread Test:
  A thread soaked in a pH-sensitive dye is placed over the lower eyelid to measure tear production in 15 seconds. This quick test gives immediate insight into your tear volume.

Tests for Tear Quality

• Tear Film Breakup Time (TBUT):
  Love this test. Quick, easy, and informative over time. A dye is placed in your eye to measure how long it takes for the tear film to break down. Normal is 10 seconds. A shorter breakup time usually indicates dry eyes. 
• Fluorescein Dye Test:
  Love this test. Again, quick, easy, and informative over time. An orange dye is used in combination with a blue light to examine the cornea for dry spots and lack of oils in the tear film. 
• Tear Film Osmolarity Test:
  This test measures the concentration of solutes in your tears relative to water. Abnormal osmolarity can be a sign of tear film instability, and thus - dry eyes.
• Lactoferrin Test:
  Measures the level of lactoferrin, a protein in tears with anti-inflammatory properties. Lower levels can be linked to dry eye conditions.

Other Diagnostic Tests

• Slit Lamp Exam:
  A microscope is used to examine the cornea, conjunctiva, eyelids, eyelashes, and oil glands closely, allowing us to see subtle changes or damage.
• Functional Visual Acuity (FVA):
  This test measures your visual acuity while keeping your eyes open without blinking, simulating real-world conditions.
• Jones I Test:
  Fluorescein dye is instilled into the eye and then the patient blows their nose. Sounds funny, but very useful to assess the lacrimal system and detect any blockages.

In Summary:

Understanding these tests can make your next eye exam less daunting. Your optometrist will pick and choose one or a combination of these diagnostic methods to determine if you have dry eyes and to create your personalized eye care routine.