They passed out from low blood sugar .They were in an accident .They are dehydrated from the heat .They have a form of genetic blindness .
What may be the reason for them losing their vision ?
My husband took me to our car and I sat down and after some time everything was good again . Another time I was sitting in class it was a hot day and everything around me was becoming dark . I put my head down on my desk and then my vision came back .