Your vision is your most important sense, learning to live without it in a civilized world is hard enough and even then you are at a severe disadvantage. Losing your vision in a survival situation would likely be fatal without the aid of others, because of this everyone should carry eye protection.
Types of Eyewear
Sunglasses will protect your eye from the bright light, wind, and some impact, but fail against hard impacts.
Safety glasses are step from sunglasses and, if tinted, will fill all of the same roles to greater effect.
Goggles off the most most protection from the elements and impact with the advantage or a complete seal around the eye to keep out sand, dust, and other irritants. They are also strapped to you head and thus harder to lose. The disadvantage of goggles is social camouflage, goggles are not generally worn by most people and as a result they tend to draw attention to the wearer.