1. When working on something up close (drawing, reading, computering, document processing) You're supposed to take a 20 sec break and look far away (like across the room or out a window) every 20 min.
-Because: seeing up close for prolonged periods of time strains your eye and makes it difficult for it to adjust and relax the lense for seeing far away. And over the years causes nearsightedness.
2. The best positions to sleep in are either flat on your back with a pillow under your knees, or just on the right side of your body with a pillow between your knees.
-Because: sleeping on your stomach compresses your internal organs, which isn't the best for them. Your heart works harder when you sleep on your leftside than in any other position. And sleeping halfway on your stomach and halfway on your side can put a J-curve in the spine over time.