The image of the black hole is not sharp. Isn't it possible, that the optics at that distance may make "optical mistakes" and this is not a black hole after all

The image of the black hole is not sharp. Isn't it possible, that the optics at that distance may make "optical mistakes" and this is not a black hole after all but maybe just some circular lightning or some darker, but not black object before some star - like in solar eclipse?