My completely uneducated, wild guess (<- disclaimer
) is that you're right: the eye will adjust to bright and low light. The most important single element of that adjustment is, to my knowledge, the dilation and contraction of the pupil. Thus, when the light is bright, less of it will be let in because the pupil contracts, and when there isn't much light, the pupil dilates to let more light through. This could probably be simulated by modifying the exposure parameter. As for this image in particular, the pupil (or camera aperture) would be contracted, so not as much light could get through. I have, however, stared directly into the sun enough times that I'll be hitting myself when I'm forty, and I still think that the terrain is a little on the dark side.