The word "goggles" is used to denote a variety of different pieces of protective eyewear. These include swimming goggles, racing goggles (used on motorcycles, in cars, or for other open-air activity such as skydiving), sports goggles, and protective goggles. The range of use is great; basically, any activity that puts your eyes at risk merits the use of some kind of goggles. Athletic goggles are used in a number of different outdoor and indoor sports. Swimmers, for example, use light, highly streamlined goggles to prevent chlorinated or salt water from irritating them during practice or a race. Athletes who play one of the many racquet-based sports, such as squash or racquetball, also use goggles, to ensure against the serious damage that might occur if a wayward ball hit one of their eyes. Also, athletes in more traditional sports frequently use specially-designed prescription goggles to help them see on the field.
Racing goggles are used during any high-velocity outdoor activity. These activities include riding on a motorcycle, in a car with its top down, and while skydiving. In each of these three pastimes, high-velocity winds can be irritating at best, and at worst damaging to sensitive eyes. Protective goggles encase the eye in a hard, clear-coating, ensuring comfort while still maintaining visibility.
Finally, any activity in which potentially-dangerous techniques or chemicals are used certainly merits the use of protective eyewear. In any chemical lab around the world, for example, you'll find that goggles are mandatory when any corrosive gas or liquid is being handled. Similarly, blowtorching without protective goggles is an obviously bad idea.