How are some people able to walk around outside with their eyes open but they are not suicidal ?

At 1 Hour 37 Minutes in the film, Tom (Malorie's Black Boyfriend) goes outside to fight the baddies who are all open-eyed and not killing themselves or seem unhinged in any way whatsoever except one says "Its a beautiful thing". So does just saying "Its a beautiful thing" make you protected from the evil thing.

But then after opening his eyes for less than a minute, Tom kills himself.

Why is he not allowed to open his eyes like the baddies ? It makes no sense at all.

It's a shame because I really enjoyed the rest of the film.