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When reading starts to become difficult around the age of 40, you may need to face the fact that it might be time to buy a pair of reading glasses.

At around your 40th birthday, you will probably start to notice that your eyes don't seem to focus up close like they used to. Extended time on the computer becomes difficult and your eyes seem slow to focus from near to far. This condition is called presbyopia, a condition that decreases our ability to focus on near objects. Presbyopia occurs as thecrystalline lens becomes less flexible, or the muscle that causes the lens to change becomes weaker.

Your first reaction, especially if you don't already wear glasses or contact lenses, may be to run to the drugstore and pick up some reading glasses. You'll be surprised at the many colors and styles of over-the-counter reading glasses, but more surprising will be the many different powers or strengths available. How will you know which one to buy? The following tips will help with your purchase of reading glasses.

Schedule an eye exam: As long as it is not an emergency, the first thing you should do is call your local eye doctor and make an appointment for a comprehensive eye examination. Most likely, you are just experiencing what many jokingly call "over 40 syndrome" or "short arm syndrome," officially called presbyopia. However, blurry vision can be a sign of serious eye problems or eye diseases. To be safe, schedule an eye exam to make sure your eye health is good.

Consider prescription reading glasses: You finally make it to the doctor’s office and your doctor recommends prescription reading glasses instead of simply purchasing over-the-counter (OTC) reading glasses. You think to yourself, "This doctor just wants to sell me a pair of glasses!" Why would anyone purchase prescription reading glasses when they could buy a cheap pair at the drugstore?" Well, here are a few valid reasons:

• Powers in OTC readers are the same in each eye. You may need a different power for each of your eyes. Looking through readers of the wrong power can cause eye strain, making one eye work much harder than the other.
• OTC readers do not correct astigmatism , oakley Flak Jacket Sunglasses;-- prescription readers do. Many people have a small amount of astigmatism. Uncorrected astigmatism can cause headaches, tired eyes and vision that seems a little off.
• OTC readers are basically, "one size fits all." Prescription reading glasses are made so that the optical center of the lens is lined up exactly at the center of the pupil. When the optical center is not lined up, you may end up looking through the side of the lens, which can cause eye strain and eye muscle imbalances.  
• Prescription lenses are made optically perfect with no distortions, waves or bubbles in the lenses. If you examine a pair of OTC readers of low quality, the lenses may have some unwanted defects.
• OTC readers do not work for nearsighted people because such individuals usually require a "minus or negative" lens. OTC glasses only come in "plus or positive" powered lenses.

   Consider OTC readers: If your eyes are such that ready- made readers will work just fine, your eye doctor will let you know. If he or she decides that they are sufficient for you, ask him what power is recommended for your eyes. Be sure to discuss your occupation and the types of hobbies you enjoy, as the power your doctor recommends may depend on what type of work you do. For example, the power prescribed for you if you spend eight hours a day on the computer will likely be different than one prescribed for you if you spend a lot of time reading or working with fine detail.

 Many people purchase several pairs of inexpensive readers and stash them in different places so there is always a pair within reach.