Roman K’s review published on Letterboxd:
The highest praise I want to give "The Lighthouse" is that it's one of those, somewhat rare, films that, one might say, can be touched and smelled. The quality of the cinematography, set design, costuming and make-up is so effective that you really inhabit the same space as the characters for the duration of the picture.
Obviously the 2 acting performances are very impressive, especially Dafoe, but that's hardly a surprise, if you're familiar with his body of work. You do get to familiarize yourself with these 2 characters through the performances and even get their insanity to infect you if you let it.
As for the story and actual point of the film I wasn't as impressed. It's a classic case of a pretentious, open to interpretation, metaphorical tale being told using all the expected tricks and methods. It left me largely indifferent and not eager to figure out any deeper meanings, because, honestly, a lot of it felt vague for the sake of being vague and artsy for the sake of being artsy. But again, I wouldn't be surprised if other viewers are much more enamored with it.
I'd still consider this a film worth experiencing, but personally wouldn't put it on any sort of pedestal. There are other films in a similar vein far more worthy of attention, including this director's own "The Witch".