Complex sentence: The most frequently used method is to measure tear production via tear break-up time (TBUT), which calculates the duration interval between complete blinks, which serves as a primary indication of regional dryness in the pre-corneal tear film after fluorescein injections.
Split into simpler sentences: The most frequently used method is to measure tear production via tear break-up time (TBUT), which calculates the duration interval between complete blinks. This serves as a primary indication of regional dryness in the pre-corneal tear film after fluorescein injections.