Answer
Eyes do have multiple origins when we look at their varied structure (for example, arthropods vs. cephalopod molluscs) and the multiple times that Pax family genes have been co-opted to produce eyes. However, given that it is members of the same gene family which have always been co-opted, there is also a commonality to their origin.
Work Step by Step
First, look at the diagram in Fig. 25.15 and see what genes have been used for eye evolution, and note the similarities (same gene family) and differences (multiple co-opting events, not always the same Pax gene). Thus, one can then make arguments for and against the idea that eyes have multiple origins.
