Mars is 1.52 AU from the sun, or 1.52x further than Earth, so the inverse square law says 43% less sun power. But the atmosphere is thinner and a different composition.
To know how the human eye actually operates on Mars, one would have to get a human eye to Mars.
I guess I meant more about how well you'd actually remember the brightness on earth after being on route so long rather than your eyes physically adjusting
This is more in line with what I was asking. The sun seems to have a psychological impact on humans. I wonder what that impact would be under both relentless cold conditions, but also when the sun never quite feels the same.
I mean, it is obviously subjective and not critical to the functioning of life or anything like that, but it just seems like one of those very subtle “death by a thousand cuts” kinds of elements that might become noticeable over time.
I don’t think anyone would directly perceive the effects in a binary logic kind of way. It would be like times when our local region is covered in thin high atmospheric clouds for weeks on end. It becomes more noticeable over time that this amount of light is not normal. I wonder about that awareness of “this is not normal” having more long term impact on psychology, not profound impacts, just some impact. I thought maybe someone had already posted images somewhere on the interwebs exploring this, but haven’t found any.