Subject: healthy and active human male, age 18-19 / active and healthy human female in her late 50s/early 60s.
The fic I'm working on now is obviously set in the future, where a community of humans are living and working on an alien planet that they've colonized. They're a self-sufficient community that produces their own food, and eventually a fungus/famine strikes, wiping out nearly all of the crop for that year.
Here's where my question is. The two characters I've described are both in good health at the beginning of the fic, but as the story progresses, everyone in the community--including them--are put on very strict rations, and nobody in the community is really getting enough food.
After about four months of this, with the rations getting smaller and smaller as time goes on, the male character is eventually locked in a prison, where he's given no food and no water until he's rescued and immediately given medical attention. Now, I've read something about dehydration potentially causing ocular hypertension, which could result in glaucoma causing partial blindness, and I want to know how long this character would have to be denied water for that to occur. Also, on a more general note, I do want to get a sense of the short and long term effects of this starvation on the human body, and whether there would be permanent effects as well. I've gotten a lot of conflicting results when trying to do research for this, and since both of these characters have medical training in my story, I really want to get this right. Any help would be greatly appreciated, and thank you in advance!