Figure 10.

Parallelism of (π/A) isotherms of human meibomian films formed of varying amounts of meibum after their correction for the areas of 0 elasticity. Curves 1 through 6 were taken from Figure 2, and the ascending portions showing the increases in elasticity have been superimposed. The corrected surface area A_c was calculated as follows: A_c = A_n + (80 − A_L), where 80 is the total surface area of the trough (in cm²), A_L is the lift-off area, and A_n is the current surface area at which a surface pressure π is measured (definitions are in Fig. 1).