How is the smoothing tendency of cornea functioned?

Smoothing tendency:

In health and in disease condition the epitheliurm has a strong tendency to smoothen the underlying irregularities, e.g., epithelial facet by epithelial plug filling. The focal detects on bowman's membrane occurs as if we are repairing defects in the road. This smoothing tendency is also active in corneas after excimer photoablation therapy. There is a tendency of the epithelium to bring the underlying area back to mitigate the refractive effect of the ablation.