In 2004, legislation was passed that allowed Americans to receive a copy of their contact lens prescription, allowing them to shop around for their lenses. Prior to this, contact lenses had to be purchased directly from the eye care provider. A prescription is usually good for a minimum of one year. While the numbers written on your contact lens prescription may look like some kind of complicated code, they are actually fairly easy to understand once you are armed with the right information.
Instructions
1. Familiarize yourself with the abbreviations. The first abbreviations you will need to learn are OS, OD and OU. OS refers to the left eye, OD refers to the right eye, and OU refers to both eyes. This should help you understand which lens each number is referring to, as many people have a different prescription for each eye.
2. Understand the refractive power of your lenses. This will be indicated by the abbreviation PWR, and should be expressed with a number. Numbers that begin with a plus sign indicate a correction for farsightedness, while numbers that begin with a minus sign are a correction for nearsightedness. The number indicates the amount of correction needed.
3. Review the size of your lens. This will be a number listed beside the abbreviation DIA, which refers to the diameter of the lens. The proper size is important as this ensures that the lens covers your eye properly.
4. Understand astigmatism measurements. If you have an astigmatism, your prescription will have a number for each eye beside the abbreviations CYL and AXIS. The CYL measurement explains the extent of the astigmatism. A positive number is used for a hyperopic astigmatism and a negative number indicates a myopic astigmatism. The AXIS measurement indicates the orientation of the lens in degrees.
5. Review bifocal measurements. If you need bifocal lenses, there will be a number beside the abbreviation ADD. This number indicates the strength needed for the bifocal part of the lens.
6. Review the color and brand. You will only have a color indicated on your prescription if you are getting colored lenses. However, every prescription is required by law to indicate a brand for the lens.
Tags: number indicates, AXIS measurement, begin with, beside abbreviation, contact lens, lens prescription