Full Idea
Aristotle would be perfectly happy with the idea that the eyes are for the purpose of seeing. Spinoza would disagree. The objects of the world, including parts of living organisms, have purposes, but obey the laws of mechanical necessity.
Gist of Idea
For Spinoza eyes don't act for purposes, but follow mechanical necessity
Source
comment on Baruch de Spinoza (The Ethics [1675]) by David Roochnik - The Tragedy of Reason p.79
Book Reference
Roochnik,David: 'The Tragedy of Reason: the Platonic logos' [Routledge 1990], p.79
A Reaction
My view is that eyes wouldn't exist if they didn't see, which places them in a different category from inorganic matter.