Figure 1. Light micrographs of the peripheral and central ferning pattern of camel tear film. A and B: Part of the periphery of the tear film showing the five outermost layers: 1) cream-colored homogenous layer, 2) dark brown
oily droplet layer, 3 and 4) small droplet layers, 5) thick ferning pattern layer. C: Part of the periphery of the tear film showing a dense ferning pattern below the peripheral layers. D, E, F: Part of the center of the tear film showing prominent primary, secondary and tertiary branching. 1 = First layer, 2 = Second
layer, 3 = Third layer, 4 = Fourth layer, 5 = Fifth layer, D = Oily droplets, F = Ferning, PF = Primary ferning, SF = Secondary
ferning, TRF = Tertiary ferning.