Why do myopic prescriptions just seem to get worse? Well, some of that is from growth and heredity (myopia results from an eye that is a fraction of a millimeter too large), but some of it is from long periods of near work. Our world is getting very near oriented, from reading and homework to computers and Gameboys. Long periods of near work without taking a break to look in the distance occasionally can result in faster progression of myopia.
Remembering the 20/20 rule can help. After any 20 minute period of near work, we should all be looking in the distance for 20 seconds (as far away as possible-out a window, down a hallway). 20 seconds is longer than you think as anyone waiting for the microwave can attest. This break reminds the eye that it still needs to see in the distance so that it may not adjust for near and let the distance go blurry. It also gives the focusing muscles a good stretch after being cramped up doing near work for a while. Your prescription may still change (as we can't control growth and heredity), but at least you can be confident that you did everything you could to slow it down.
Parents can remind their children to look at the birds in the trees once in a while and students and office workers now have a good reason to take a break. Tell your teacher or boss that your optometrist told you to take a break and look in the distance!
Happy reading with frequent breaks!