Final answer:
The problem relates to the physics concept of angular resolution and uses Rayleigh's criterion to calculate at what distance the human eye can differentiate between the two headlights of a vehicle.
Step-by-step explanation:
The question is regarding the angular resolution of the human eye and at what distance the eye can differentiate between the two headlights of a vehicle. To calculate this, we need to use the formula for angular resolution based on Rayleigh's criterion which is θ = 1.22λ/D where θ is the angular resolution, λ is the wavelength and D is the diameter of the pupil. Using an average wavelength for visible light (550 nm) and the pupil diameter (0.40 cm), we can find the smallest angle at which two points can be resolved. We can then use the angle to determine the distance at which two points, in this case, car headlights, can be resolved. In traffic safety, it is generally advised that drivers should switch to low beam when within a certain distance of an approaching vehicle to prevent blinding the other driver but that distance is specified by traffic laws, not by the resolution of the human eye.