But from Mr.
Stephen's account of his uncle's sudden loss of sight in the right eye after a fall, I judged that Jeffrey had also suffered from dislocation of the lens and therefore had a tremulous iris in the right eye.

The patient, Graves, evidently had defective vision in his left eye, as proved by the marks made behind his ears by the hooked side-bars of his spectacles; for it is only on spectacles that are intended for constant use that we find hooked side-bars.

But Jeffrey had defective vision in his left eye and wore spectacles constantly.

Lastly, the patient Graves was suffering from chronic morphine poisoning, and morphine was found in the body of Jeffrey.
"Once more, it appeared to me that there were too many coincidences.
"The question as to whether Graves and Jeffrey were identical admitted of fairly easy disproof; for if Graves was still alive, he could not be Jeffrey.

It was an important question and I resolved to test it without delay.