Use Safety Eyewear
This is pretty much a no-brainer. If you are mowing the lawn, cutting wood, pounding nails, sanding, or doing almost anything that involves flying objects, wear safety glasses.
If you play sports like racquetball or hand ball, wear eye protection.
It is really hard to have 20/20 vision if you damage your eyes or get hit in the eye with a fast flying ball.
But what about going without glasses all together?