[fouric]

I think the parent comment is aimed at people who have trouble waking up because they didn't get enough sleep, not just because they're sleepy.

[gremloni]

Sunlight in the eyes doesn’t fix that issue either.

[fouric]

Um, it actually does, if you have a circadian rhythm sleep disorder (for which one of the treatments is light therapy, aka getting sunlight in your eyes[1]).

Conversely, I'm not aware of any sleep disorders that are treated by drinking a glass of water in the morning.

[1] https://en.wikipedia.org/wiki/Circadian_rhythm_sleep_disorde...

[gremloni]

Anecdotally it seems to work well even if I’ve had only 5-6 hours of sleep that night.

[fouric]

I don't think that you have a sleep disorder, and so your anecdote isn't even usable as anecdata for those of us who do (including the top-level comment, which reads "I struggled with sleeping for 20+ years" - this isn't just "occasionally sleeping poorly").