Hair growth has three phases, The anagen, catagen and the telogen phases. Depending on where the hair is located, the anagen or the growth phase vary greatly. For the eyelashes it is only in this phase for about 30 days. Due to this, the eyelashes don't grow that much.
Did you mean mechanical ? If you do mean mechanical then here's the answer to your question:
Mechanical digestion is when the food is being broken down physically into smaller pieces from the mouth and chemical digestion is when the food is being broken down into substance particals starting from the saliva and proceeding through the small intestines.
