Lifting the Lid on Tear Film Dynamics: Tear Film Movement Upon Vertical Gaze Change

When examining the ocular surface, patients are required to look straight ahead and the effects of vertical eye movement on tear film behavior are not considered despite it being natural and common to change gaze without blinking. This exposes parts of the bulbar conjunctiva previously covered by the eyelids and therefore not covered by the tear film during the preceding blink. This study investigates how the tear film behaves when presented with newly exposed areas of ocular surface due to vertical eye movements. The tear film dynamics of a sequence of vertical open-eye gaze maneuvers (upgaze-downgaze) were studied in 15 participants with no ocular surface related complaints (OSDI