What is a common effect of driving while fatigued?

Answer: C — Difficulty keeping eyes open

Driving while fatigued significantly impairs your body's ability to function optimally, including keeping your eyes open. Fatigue can lead to decreased alertness and drowsiness, causing your eyelids to become heavy and making it difficult to maintain focus on the road. This inability to keep your eyes open can result in decreased reaction times and a higher risk of accidents, as your awareness of your surroundings diminishes. In contrast, the other options do not accurately represent the effects of fatigue. Increased speed is generally a result of recklessness rather than fatigue. Misjudgment of distance can be a consequence of reduced attention due to distractions or intoxication, but it is not primarily associated with being tired. Enhanced vision is not a factor at all; fatigue typically leads to visual impairment rather than improvement.