ArticlesA Guide to Eyeglass Lenses
Glasses Can Help Even Young Children
As your eyes age, their lenses become less flexible, and they slowly lose their ability to focus on nearby objects. It's an ongoing, lifelong process called presbyopia, which you begin to notice between ages 40 and 45, when the condition starts to affect close-up tasks, such as reading. It requires some attitude adjustment, especially if have to start wearing glasses for the first time. Presbyopia affects almost everyone over the age of 50.
Until now, you could choose your own working distance: You could hold things wherever you wanted, and your eyes would adjust. But eyeglass lenses can't mimic what the eyes actually do. Glasses can help you focus, but they don't have the depth of focus your eye muscles provide.
So, even with glasses, you may still have to adjust to compensate for vision changes. That may mean holding reading material at a certain distance, raising or lowering your eyes or moving your computer terminal.
Fortunately, there are corrective lenses that can make those adjustments less complicated. Lightweight lenses put the correction in your glasses exactly where you need it for your comfort.
Single-power lenses correct for only one visual deficiency such as nearsightedness, farsightedness, or astigmatism. Glasses worn only for reading are an example of single-power lenses. People with more than one vision problem need multifocal lenses.
The most common solution for reading glasses is the bifocal, a lens with two different prescriptions. The one on the lower half is your reading prescription; the one on the upper half is your prescription for distance vision.
Trifocals have distance correction on top, reading correction on the bottom, and a band of "intermediate vision" in the middle, for seeing things at arm's length. Intermediate vision correction can be helpful for people who spend a lot of time working at a computer terminal.
Progressive or no-line lenses have multiple focal points between near and far that allow you to see all distances.
An option that is becoming popular is to wear task-specific lenses you keep at your desk and wear only for working on your computer. Many people don't like to have to change glasses if they're up and down from their desks a lot, but it's a positive solution for some people.
Here's how you can further ease your vision adjustment:
Get a complete eye exam in which your eyes are dilated. Although it is likely that you are experiencing presbyopia, you should get a complete eye exam whenever you notice changes in vision. These exams help to screen for eye diseases, such as cataracts, macular degeneration, and glaucoma.
Use more light than you're accustomed to when you read.
Keep your glasses clean.
Have your glasses adjusted if they are slipping down your nose or are otherwise uncomfortable. It sometimes takes four to six hours of continuous wearing for pressure points to occur that you may not notice during a normal fitting.
You should find another doctor if yours doesn't offer periodic adjustments or ask lots of questions about your lifestyle and interests when examining you.
Take care of your eyes--they are the only ones you have.