Would the 'black spot' be picked up by the eyes, or would it be blurred, kind of a peripheral image? (ok, I know I dont know, I know you probably dont know for sure, but I know someone knows more than me.)
Not sure what you mean by "picked up by the eyes". Your brain-image would be formed both by what the eyes "picked up" and by what they did not pick up. but the sharpness of the outline of the hole is an interesting question. We're way into the hypothetical here and I suppose it would depend on the coverage of the light pipes. If the coverage were perfect (hypothetically) then the outline would be sharp
Black holes would be a different story as space is curved around them relative to their mass. As in the famous Einstein proof, objects directly behind them would appear in front or at least peripherally which might "blur" the edges of the image. We need a Hawking here.
Dunno, just some thoughts.