In what scenario is it illegal to use high beams while driving?

Using high beams while there is oncoming traffic is illegal because high beams can significantly impair the vision of drivers approaching from the opposite direction. The bright light from high beams can blind oncoming drivers, increasing the risk of accidents. To ensure safety for all road users, it is important to switch to low beams when you are within a certain distance of oncoming vehicles, typically about 500 feet. This practice helps maintain visibility while protecting the safety of others on the road.