What is the normal tear break-up time (TBUT)?

The normal tear break-up time (TBUT) is typically regarded as being in the range of 10-12 seconds. This measurement is crucial in assessing the stability of the tear film on the surface of the eye. A tear break-up time within this range suggests that the tear film is stable enough to keep the surface of the eye adequately lubricated and comfortable, which is vital for clear vision and overall health of the ocular surface.

When TBUT is less than this range, it may indicate potential dry eye conditions or issues with tear production or stability, leading to discomfort and visual disturbances. Understanding the normal range is therefore essential for eye care professionals to diagnose and manage various ocular surface disorders effectively.