I need to know the meaning of "the visible becomes inevitable."

In Chapter
37, Enzo is diagnosed with 'degenerative arthritis caused by hip dysplasia.' He finds that his
movements are no longer smooth and easy, and he surmises that the diagnosis foreshadows the
beginning of a journey that will ultimately lead to his demise.

With my diagnosis, I knew, would come my end. Slowly, perhaps. Painfully, without a
doubt; marked by the signposts laid out by the veterinarian. The visible becomes
inevitable. The car goes where the eyes go.

Enzo is resigned to his fate, but more than anything, his fundamental goal is to be
reborn as a man in his next life. In the story, Enzo believes that everyone is the master of his
own destiny, and it is his destiny to be reborn as a human being.

...we are the creators of our own destiny. Be it through intention
or ignorance, our successes and our failures have been brought on by none other than
ourselves.

Enzo's chronic condition worsens as the story
concludes, but he is unperturbed because he is more than ready to relinquish his canine
existence on earth. Both his mortal and immortal eyes are turned towards his goal. The visible
(the long-looked for destiny) becomes inevitable and manifests itself when one's energies are
focused on it. Hence, the 'car goes where the eyes go:' where the mind leads, the body will
follow. Hope this helps!