You could, of course, just close your eyes, but that would create other problems. The best protection against wind, flying objects, sand, dust and - of course - the sun, still comes in the form of goggles. In fact, we say they are part of every motorcyclist's standard equipment.
Depending on your personal style, or the preferred conditions in which you get on a motorcycle, there are three main subcategories.
Sunglasses, helmet goggles and motocross goggles
Sunglasses: most of them are worn underneath the helmet like normal glasses. Many helmets have this provision as a standard feature.
Helmet goggles: the retro/vintage look is pretty much standard with these goggles, which are - often - worn on top of the helmet with an elastic band. However, you don't have to, as there are also models that you can wear inside the helmet, which is especially useful if traditional goggle legs bother you.
Cross goggles: these goggles are specifically designed for sports and games in harsh conditions. Dirt-resistant elastic, large size, often the option to work with 'tear-off' lens.
You can find extra parts - in the form of separately available lenses - and helmet masks here as well.