Fig. 2

Morphological zones in a normal tear microdesiccate imaged with phase contrast (Ph3) microscopy. A hardly seen hyaline zone I Z1 surrounds the whole circular area of the body of the tear desiccate in close proximity to a clearly structured transition band Tb. At the centermost area of the desiccate (demarcated by a black circumference) abundant major fern-like crystalloids feature zone III Z3. A compact homogeneous band of short fern-shaped or leaf-shaped crystalloid structures located between the transition band and zone III represents zone II Z2. Some bright filamentous structures (f) can be also seen as part of zone I