"You can't depend on your eyes if your imagination is out of focus"
Initially I had to research this quote, I wanted to understand what other's thought about Mark Twain's words. What I have come up with is that many things are subjective. Some said if our imagination isn't under control, our eyes can't see straight (paraphrasing of course).
So let's go with that thought, because I can get behind it. I'm even willing to think about times when people are sleep deprived, many symptoms can set in - paranoia (in extreme cases), poor mood, reduced reaction time, and/or generally feeling tired. If a person shows signs of any of these potentially their imagination can start to run wild, which would in turn deceive our eyes.
So what can we do to help ourselves:
1. Get an appropriate amount of sleep. (This can vary for each person)
2. Exercise is a thing! It helps improve sleep quality and duration, heart and lung improvement, weight control, it can also improve your mood.
3. I always find for myself, when I am adequately hydrated, my body feels entirely different. I feel loose and my organs feel like they breathe and work differently.
At the end of this, may hope is that we take better care of ourselves by practicing anything that will help to keep our eyes from being deceived.