FREQUENTLY ASKED QUESTIONS ABOUT MAGNIFIERS

At Senior Shopping Network we want you to have the best experience from your magnification purchase. Good magnification, like good vision, is a combination of factors. We are including below the 11 most common magnification questions and answers to direct you to the best product to meet your needs.

QUESTION #1: How do magnifiers work?

The greater the curve of the lens, the greater the magnification power. If you were to slice a typical magnifier lens in half, you would see that by being thick in the middle then tapering to very thin edges, a curved surface is created. If both surfaces are curved, the lens is approximately elliptical (football) shaped; if one surface is curved and the other is flat, it is dome shaped. The curved surface of the lens bends light rays in such a way as to make an object under the lens appear larger (magnified). The larger and thinner the lens, the lesser the magnification power.

QUESTION #2: What power of magnifier is best for me?

While it is human nature to choose the most powerful magnifier for reading enhancement, that may not always be the best choice. Most Senior Shopping Network customers purchase magnifiers to enhance daily living activities such as enlarging the printed word, finding a spot on a map, and magnifying craft and hobby objects for better viewing. Too powerful magnification may disproportionately magnify individual words and letters out of context with the sentence being read and, at the same time, reduce the overall viewing area. Because of how we are trained to read, when this happens we may lose some of the general meaning of our story or article. For enhancing daily activities, it is recommended that you start with a magnifier in the 2X to 5X range.

In addition, for most applications, many consumers and magnification experts report that improved lighting (or an illuminated magnifier) is too often overlooked and might be considered before taking a large jump in magnification power. For fine work one might consider the purchase of a magnifier equipped with a more powerful spot lens. This works by the very same principle as bifocal glasses. For instance a 2X magnifier with a 4X spot would be designated as having a 2X/4X lens. For moderate reading enhancement without fine details, flat sheet (Fresnel) magnifiers (with or without stands and illumination) are a popular choice. For more information on Fresnel page magnifiers, see Question #10 below.

QUESTION #3: What is magnification power?

Magnification power is the extent to which a viewed object is enlarged over its actual size and is designated by an “X.” Thus, a 2X magnifier gives an image that is double the size of the actual object. Bearing in mind that 1X is the true unmagnified size (100 percent) of the object, 2X makes the object appear 100 percent larger than it actually is and a 4X magnifier makes the object appear 300 percent larger. Remembering how a magnifier works, a 4X magnifier would have a greater curve to its surface than a 2X magnifier.

KEEP IN MIND... The total Area of the object is what is enlarged. For example, when viewing a 1" X 1" stamp (Area=1 square inch) with a 5X magnifier (400% larger), the Area would be multiplied roughly four times, giving the appearance of a stamp that is 4 square inches, or 2" X 2". NOTE: This is a simplified version of the actual equation to demonstrate an easier-to-understand example. Optimal magnification also depends on correct focal length.

QUESTION #4: What is the difference between "X" power and Diopters?

Some websites, retailers and manufacturers will often list their magnifier power in "Diopters." While this appears to be a stronger power magnifier, this isn't the case. Diopters are simply another way to measure the bending of light. To figure out the comparable "X" power, divide the Diopters by 4, then add 1.

For example: A magnifier listed at 10 Diopters would actually be 3.5X. (10 diopters divided by 4= 2.5 + 1= 3.5X).

QUESTION #5: What is focal length?

Focal length is the distance from the center of the magnifier to the object that gives maximum magnification, clarity and viewing area. While there are reported optimum focal lengths for magnifiers of various power levels, in working terms, consumers may be just as satisfied with some trial and error. With hand-held and flexible magnifiers, you can experiment by moving the magnifier toward and away from the object until the best image is achieved. With stand, some collector’s, loupe-type, dome and bar magnifiers, the focal length is pre-set by the stand or the construct of the magnifier. Certain hands-free and hobby helper magnifiers allow the object itself (and magnifier) to be moved in order to achieve the best clarity. Regardless of the type of magnifier, it is a general rule that as the magnification power increases, the focal length decreases. By example, the standard focal length for a 2X magnifier is approximately 10 inches, whereas the focal length is 5 inches for a 3X magnifier.

QUESTION #6: What is an Aspheric Magnifier?

Aspheric magnifiers, unlike spherical magnifiers, provide an "orthoscopic" image. Aspheric lenses have variant radii designed to produce a sharp image right to the edge of the lens. This allows for consistent, distortion-free viewing over the entire lens area with greater magnification over a surprisingly wide viewing field. Aspheric lens technology results in magnifiers that are somewhat more expensive than spherical magnifiers, but those who use them say they are well worth the extra cost.

QUESTION #7: What magnifier is best for Macular Degeneration and other serious low vision conditions?

The severity of Macular Degeneration varies from patient to patient as does the response to various low vision aids such as large print books, large lettering and numbering on phones and computer keyboards and, of course, magnification products. Macular Degeneration patients who have been helped with magnification seem to prefer a very clear glass or optical acrylic magnifier in the moderate 2X to 4X range accompanied by bright illumination. Many also select a rim-free magnifier. Keep in mind that other attributes of a magnifier such as weight, portability and the handle design will also be important to a Macular patient. Vision aids may be an important part of a total treatment program but should never be considered a substitute for regular medical evaluation and treatment by an appropriate specialist.

For more severe cases of Macular Degeneration, retinopathy, glaucoma, and cataracts you might consider looking into one of our Video Magnifiers (click here) , which allow much greater magnification potential than traditional handheld magnifiers. (see Question #10 for more information on Video Magnifiers).

For more information about Macular Degeneration, please visit our partner site (but make sure to bookmark us & come back!), The Macular Degeneration Foundation (click here).

QUESTION #8: Which is better--a glass or an acrylic lens?

Some us remember the little plastic magnifier on a chain that we had in grade school. Over the course of several years, thermoplastic technology has become so very much improved that the choice of optical acrylic or glass is nothing more than a matter of personal preference. In fact, how many of us have glasses with optical plastic lenses? Glass magnifiers remain highly regarded for fine clarity and surface hardness. Optical acrylic lenses are also manufactured for clarity and scratch resistance, plus many are very lightweight. Certain magnifier styles such as vintage or rim free may be better constructed using one material or the other. Today, the consumer can be fairly well assured that other attributes of a magnifier should be considered at least as important as the material.

QUESTION #9: Why don’t manufacturers make magnifiers with high power, crystal clarity and a large viewing area?

This is a common question. First of all, remember that the power of clear glass and optical acrylic magnifiers is directly related to the amount of the curve to the lens and the curve of the lens is inversely related to its size. That is, higher magnification requires smaller lenses, and a high powered lens with a large viewing area would be impractical, cumbersome and heavy, and for everyday home-office use, it would likely distort the image of objects being viewed. Very high power magnification with clarity is usually for technical-scientific work such as microscopy, textile examination and photography. These applications often require a series of lenses and accommodate only a very small viewing area, and these are not applications our customers are seeking. However, to serve daily living needs and hobbies, Senior Shopping Network has a wide variety of clear image magnifiers available in the moderate 2X to 4X magnification range with the largest practical viewing area we can find. Additionally, SSN carries some selection of magnifiers over 4X power and several magnifiers with spot lenses for close-up work.

For customers who desire some reading assistance without fine detail work and crystal clarity, a flat page (Fresnel) magnification sheet might be the answer.

QUESTION #10: What is a Fresnel magnification sheet?

A magnification sheet is a special kind of magnifier formally named for its inventor, Augustin Fresnel. The Fresnel magnification sheet is usually made of one of the various plastics and is about the thickness of a credit card.

Personal-use Fresnels may be moderately flexible to rigid and range in size from a credit card reader to a full-page magnification sheet (with or without a stand and illumination). Very basically, the typical Fresnel sheet is smooth on one side and imprinted or scored on the other side with a series of concentric rings. Each ring is slightly thinner than the next, giving the magnifier the ability to focus (reflect) light toward the center.

Magnification sheets for home or office use are lightweight, thin and rather durable. Depending on the application, personal use magnification sheets usually come in 1.75X to 3X power and are used almost entirely for reading enhancement. Consumers need to know that the image quality of the Fresnel is not as good as clear glass or clear optical acrylic (making it a little more difficult for people with more severe vision problems, such as advanced Macular Degeneration), but there are several useful applications such as the popular full-page magnifier.

In order to gain the greatest benefit from the Fresnel-style magnification sheet, it is important to use it correctly.

1. The sheet should be held level over the object being viewed and at the recommended distance. This will be pre-set in magnification sheets in a stand.

2. Focus your eyes directly over the magnifier at 8 to 12 inches away. The line of sight from your eyes to the object viewed should be a straight line passing through the magnification sheet at a 90 degree angle.

3. The object being viewed should be well lit but external light should not be directly over the magnifying sheet because of the potential for glare.

4. Wherever possible, the object being viewed should be illuminated from a light source aimed between the lens and the object rather than through the lens to the object.

QUESTION #11: What is a video magnifier?

For those with an advanced or serious low vision condition, a video magnifier (VM) is a powerful electronic device that uses a camera to project an enlarged image of text or objects onto a screen (TV, computer monitor, or self contained). Although there is a wide selection of options and magnification levels, it is generally accepted that VM’s fall into one of two categories – portable and stationary (desktop).

Considerable technological effort has been directed at developing lightweight, completely portable video magnifiers. One type of portable is the camera-mouse model that can be quickly and simply connected to most TV’s or PC’s. . Although the camera-mouse is the least expensive VM, the magnification power can be considerable (up to 20 times or more depending upon the screen). Another version of the portable is the completely portable, battery operated handheld that projects onto its own built-in small screen. Intended primarily for “spot use,” the typical magnification range is from 2 – 10 times or more.

Desktop models have a camera mounted/mountable over a reading surface and can project onto a TV screen, a computer monitor, or a built-in screen. Practical magnification levels may be up to 50 times plus depending upon screen size and camera capability. Stand-alone, sometimes called in-line or side-by-side, models have a built-in screen dedicated entirely to the magnifier. “Camera-only” desktop VM’s may be less costly and more portable since they can be connected to most existing TV’s or computers.

Like with traditional magnifiers, magnification power of a video magnifier is of primary concern to the user. Many manufacturers reply to this concern by offering varying magnification levels and choices along with a number of other options, some of which are mentioned in the next paragraph. Also, remember that magnification level is affected by the size of the screen. In addition to magnification power range, there are a number of other possible features found in video magnifiers. A few options that are popular with low vision users include reverse mode (white text on black background), various colors for text and background, full color display, brightness adjustments, auto-focus, and more.

Potential VM users should first identify their purposes (reading, hobbies, school work, writing or spot use) and decide which model has the best combination of attributes to fulfill their needs. If one is unsure, consultation with an appropriate specialist, distributor or agency may be helpful. Finally, make sure you purchase your VM with a warranty and from a company with a reasonable return policy.