What Might Be Causing Ghostly Optical Illusions And A Full-color Image Of A Stranger?

I seem to have completely recovered, But I am amazed by the Optical Iillusions in the form of ghostly human beings that I have experienced twice so far.. The last one was a full color image of a man I barely knew and recognized. The image(s) then simply wander off to other parts of my living quarters and, of course, completely disappear. Doctor, could you please comment on this phenomenon ? Also, What is the life expectancy with a 95 & carotid artery blockage?