Scared of seeing things out of the corner of my eyes. Whats my fear called?

by Jess
(England)

I am scared of seeing things out of the corner of my eyes!

It started when i was 6 i saw a label on something and for some reason because i had seen it out of the corner of my eye i was conviced it was a little green monster and when i looked properly i decided it was invisible so i jumped around the room kicking slapping and screaming!

What is the fear called?