A short distance
This will depend on the person and the weather conditions. If it is nice out, you will be able to see a longer distance ahead while if it is snowing or icy, you will need to go slower to be safe.
1/4 of a mile
They have orbits at the distance of Jupiter and 60 degrees ahead of or behind it
See link
the visibility
sight distance
the visibility
Within the distance you can see ahead
sight distance!!!
make sure you can stop in the distance you see ahead of you.
You should scan ahead as far as you can see
sight distance
They can see 5 miles ahead. Bears distance vision is roughly the same as ours, although they can see better at night than we can.
A short distance
When driving, always look as far ahead as it is possible to see. Take the opportunity to look past other vehicles, through gaps in buildings, hedges, fences etc to see just a little further along the road. The further ahead a driver sees, the more time he has to react to hazards and to assess the upcoming risks. In towns, it is often hard to see more than a few hundred feet and perhaps less than that. In rural areas, the distance may be approaching a mile or more. However far you can see, that is the ideal minimum distance to be looking ahead.
as a defensive driver you must follow the car ahead of you at safe distance of?