Does anything have an objective purpose? For example, maybe the purpose of eyes is to see. Or, is all purpose subjective? My guess is that nothing has an objective purpose, because the concept of purpose is purely subjective. But what have philosophers thought about this topic?
Eyes do not have a purpose, they have a function: The function of seeing.
From the viewpoint of biology and specifically from the viewpoint of the theory of evolution the capability of seeing and the function of the eyes as the correponding tool have developed in accomodation to the ecological niche of the human species. The capability of seeing improves orientation of human beeings and provides them with more information about their surrounding. That’s a big advantage.
But it is one characteristic of the theory, that biological evolution does not realize a predetermined plan or purpose. It is not teleological.
Acting purposeful is the capability of human beings and certain other animals.
But it can be discussed whether even this interpretation hides the fact, that also humans are causally determined by their previous experiences and the assessment of their results. This leads to the question how to conciliate free will and determinism. If that’s possible, then our purposeful action is the subjective, first-person view of a causally determined mechanism.