Some can inform cyclists of their current and average speeds, how long and how far they have been traveling, and their heart rate and temperature. For both safety and comfort, rider accessories are as important as bicycle accessories. Below are descriptions of some personal accessories. Helmets are a bicycling-safety essential, and wearing one during cycling is a legal requirement in some states and a prerequisite for participation in most organized bike rides. Well-ventilated helmets designed aerodynamically and for high nighttime visibility are widely available.
Some helmets have a built-in sun visor.
Helmets struck in a collision should be discarded and replaced. Helmets are adaptable for comfort and to atmospheric conditions with various helmet liners, cycling caps, and headbands. Visorless helmets are combinable with a visor, which can keep rain off a cyclist's eyeglasses. A visor, goggles, or sunglasses can protect the bicycler's eyes from dust and airborne debris. Like sunglasses, tinted visors and tinted goggles can otherwise improve daytime visual comfort, even in hazy or cloudy circumstances.