Taking the dry eye test manually
- Obtain a stopwatch or clock.
- Blink 2 times, then stare straight ahead, taking care to start timing immediately after your second blink.
- Avoid blinking for as long as possible.
- Note the time on the clock when you begin to feel eye discomfort (burning, grittiness, dryness, etc.)
- The SBUT is the amount of time (in seconds) that passes between your last complete blink and the moment you experience eye discomfort.
If your SBUT is 5 seconds or less, you may have dry eye, because the tear film on your eyes is breaking up too quickly, leaving the surface of your eyes unprotected. If you think you may have dry eye, consult your eye doctor for proper diagnosis and treatment