“Eye exams?”

Anything can be detected with technology

Although I have never seen one, I just looked at pictures of optic nerve micro chips. They are very obvious, and would be easily seen by any eye physician.
SO

No, we could not. We can see only the very frontmost part of the optic nerve. The rest of its 7+ inch length is buried deep inside the skull and brain, where it is extremely well protected. No such devices exist at this time, and it is unlikely that they ever will. The concept is something out of a science fiction novel or far out conspiracy theory. I can't imagine what such a device would accomplish. There are 10 million fibers in the optic nerve of each eye, crammed into a space the size of the lead in an ordinary pencil. There is no room to put anything foreign into the optic nerve without damaging it severely, causing blindness, and no effective way to connect any artificial device to the nerve in any way that would produce any sort of useful result.

Outside the eye nerve, no. Inside the eye, yes.

Dr. LMJ

It depends on what the actual size of the microchip is. A one millimeter-sized object on the surface of the optic nerve ("optic nerve head") would be easily seen with a dilated slit lamp exam. A 0.1 mm diameter object might be mistaken for an anatomical defect. Any objects internal to the optic nerve head would not be detectable by an office exam and would require some type of imaging. An MRI of the optic nerve would probably detect a synthetic implant larger than 0.5mm. If the object incorporates any metal, a CT would be useful with the same size limitations. Hope that helps!