so over the last 3 days i've been mugging really hard (or at least trying to) for uni exams which are in 3 days' time but while i'm doing my revision at my study desk I keep seeing insects move within my field of vision. some insects i've "seen" are cockroaches and ants with wings. but when I move my eyes to focus on where the insect is, it's not there. this has happened at least 3 times today and i'm afraid it might get worse and become hallucinations. 

i have not had these symptoms before and it's scaring me. either my eyes are really tired or i'm really starting to see things. is this how visual hallucinations start? i am definitely going to ask my psychiatrist but my next appointment is in july. in the meantime i would like some reassurance or clarification, thank you :3