I lost vision in my right eye after failed retina detachment surgery damaged the optic nerve. I don’t see blobs of light like you describe, though I do see a dim pattern of swirling lines when I walk into a dark room. Also, weirdly, if there’s a sudden noise while I’m in the dark, I often see a flash of light go off, like an old flashbulb. I’m guessing that’s my visual system somehow rewiring itself to other sensory input.