This movie will keep you hooked whole time, good screenplay, good pace, good acting, good thrill...
BUT at the end will make you question why you watched and wasted time on it.
Too many unanswered questions.
Typically one unanswered question is usual which audience can interpret the way they like, with many different interpretations possible.
But in this movie neither you get to know what was the thing that caused people to kill themselves, neither you get to know why some people were immune to it, nor you get to know why they attacked and forced other people to see it, nor you get to know what the future could have been for them other than ending in a small school for blind, how would people with eyes live in that school without issues. Nothing. Even the river journey with two kids through rapids was absolutely non confirmable. Something not possible without seeing the way they accomplished it.
Looks like they got the concept, started with it and then didn't know what to do with it.