If you are like me, you are confused by the terms pertaining to magnification. Here is an attempt at some clarification. I wish to thank Dazor for their helpful information.

What is POWER?
Power refers to how much larger an object is made to look through a magnifying lens. Light rays are bent by the curved lens surface resulting in an image that looks larger than the actual object. Power is the ability of the lens to increase the visual size of an object. Power is typically indicated by an "X" such as 2X or 4X. As an example: a 3X magnifier is three times larger than the size of an image, a 1X magnifier doubles the size of an image, or is one times larger than the original image. This power classification system is what most magnifiers will list, although some manufacturers follow a different convention. These manufacturers add one to the power classification, thus our 3x example above would be 4x and describes an object as being 400%, (rather than three times larger). This certainly causes some confusion! We will utilize the first, more common, standard.

What is a DIOPTER?
Diopter is not the same as power. Diopter refers to the curvature of a lens. As the curvature increases, light rays are redirected to fill a greater portion of the viewer's retina, which makes the object look bigger. As the diopter increases, you shorten the focal length where you see the magnified object clearly. As the diopter increases the lens becomes thicker and the curvature greater. Higher diopter lenses have greater magnification power. One diopter is roughly 25% of each power (X). Thus, a 4 diopter lens provides an image that is 100% larger, or roughly equal to 1X.

What is FOCAL LENGTH?
Focal legnth is the distance from the center of the lens to the point where the light rays converge and the object is in optimal focus (focal point).

What is FIELD OF VIEW?
The field of view is the size of the area that is seen through the magnifier. The field of view decreases as the power increases. More powerful lenses make small details look big, but less of the total object is visible. There is a trade-off for the viewer who must decide between the size of the field of view, and the amount of magnification .

What is DEPTH of FIELD?
The distance that a magnifier can be moved from an object, and still have the object in focus, is the depth of field. With depth of field, the higher the power, the shorter the depth of field.

What is the relationship between LIGHT and MAGNIFICATION?
Proper lighting is equally as important as magnification in achieving a good viewing situation. Increasing light levels results in better vision. The better the quality of light used with a magnifying lens, the less power is needed. This is very desirable, because when less magnification is required, the user has a bigger field of view.

The subject of magnification can be confusing. In the months ahead we hope to present more information to make this subject more understandable and to make it easier for you to purchase the right equipment to meet your vision needs.

There are many exceptional products to aid with magnification that can be found at Life with Ease. Check them out at:
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