Nearsightedness is a medical symptom where a person can only see objects that are near his or her eyes. To them, attempting to see an object that are far away results in seeing blurry objects. Someone who is nearsighted requires either glasses or contacts to be able to see clearly objects that are far away.1
The reason nearsightedness occurs is fairly simple to understand. When our eyes focus on an object, the lens inside our eyes compress and relax depending on the object's distance from our eyes—when you focus on objects that are up-close, the lenses compress; when you focus on objects that are far away, the lenses relax. There is a muscle surrounding the lens that accomplishes this feat of precision compression of the lens, called the ciliary muscle. Here is a diagram of the eye for your reference, courtesy of Wikimedia:
If the ciliary muscle is overworked too much for too long (you focus on near objects for too long and too much), it can “tighten up,” no longer able to relax, kind of like the muscles of body builders that are always bulky and unable to relax. When this happens, the lens inside our eyes stay compressed, which in turn prevents our eyes from seeing objects far away.
Nearsightedness is more common in today's world as more and more profession calls the need to read and use computers at work. At 8 hours/day, the ciliary muscle is overworked for most of today's business people.
When a person becomes nearsighted, he or she usually gets a pair of glasses or contact lens to correct for their symptom. This is fine, except it does not alleviate the cause of the problem, which is the prolonged focusing on near objects such as the computer screen or documents. There are several things one can do to prevent further degradation of the eyes:
- Relax the eyes while working. Intermittently focus on objects that are far away, or take off the glasses (if you wear any.)
- If you know you'll be focusing on a close-by object for a long time, do not wear any glasses or contact lens while working with them. If you need glasses or contact lens to be able to work, wear weaker prescription that will keep your eyes relaxed (relatively speaking) while working. Many optometrists will allow you to get “reading glasses” that have weaker prescription.
One last note: Optometrists will often assure you that your eyes will stop getting worse soon after your body is fully grown. This may have been true for a typical person 30 years ago, but this is no longer true for today's business people that work 40+ hours a week in front of computers. A person's eyes will stop getting worse (your eyes will end up with a “fixed focus”) after about 40 years of age; until then, assume your eyes will continue to get worse and wear reading glasses or weak contact lens while working, and wear stronger prescription only when you will be outside for a long time. Stay safe, though—if you drive, always wear proper prescription for the driving conditions.
