Funny, I literally just finished the series a few hours ago.
I thought the eyes were pretty good at helping us distinguish who's sane or not.
Personally, I don't think its right to say nothing 'really happens' till the last few episodes. It's supposed to be a horror/mystery genre and it does a really good job at keeping you on your toes guessing what the heck is going on.
I'll agree the pacing is slow in the beginning, but once the story started rolling I was completely onboard.
Not available for work at this time. Apologies for any inconveniences.