Seeing Shadows: A Peripheral View

Why do we see shadow entities in our peripheral vision and then they suddenly vanish? I just recently recorded the second edition of the audiobook version of A Walk In The Shadows: A Complete Guide To Shadow People, and there are some new additions! Just over a year ago, I released the print version of the second edition, which included over 40 pages of new content, so the audiobook companion has been a long time in coming. The additional content to the new audiobook version (due out in March) i...