Simultaneous examination of tear film break-up and the lipid layer of the human eye: a novel model eye for time course simulation of physiologic tear film behavior (Part 2).

This article describes a model eye created to mimic the three-layered human tear-film. The model replicates the properties of the mucin, liquid and lipid layer as well as the time-course behavior including blinking process and tear film break-up for measurements with the tear film sensor described in Part 1. The setup basically consists of a sphere that is moistened by a dilution of tear film substitute. Therefore, the time point of the first break-up strongly depends on the consistency of the dilution. By means of an integrated heater, the evaporation rate of the artificial tear-film can be increased. To illustrate the applicability of the model eye, exemplary images during tear-film simulation, taken with and without using the heater, are shown. All images were captured by the sensor. Results and other potential applications are briefly discussed.