Optical devices fall into three very general categories:

"Near" devices

"Near" devices are for close work, such as reading, sewing, and cooking. The most common devices in this category include:

Stand Magnifiers

The simplest device for reading is the stand magnifier. When placed on a page this type of magnifier is automatically in focus for reading.

The advantages of a stand magnifier are:

• Inexpensive and readily available. The stand magnifier shown in the photo here is available at Sammons Preston Roylan web site and at the Lighthouse online.
• The focusing distance is set by simply placing the magnifier on the page
• Helpful for individuals with poor motor control.

The disadvantages of a stand magnifier are:

• Book bindings may present a problem, as the magnifier may not remain in a stable or fixed position
• Selecting and positioning appropriate lighting might be problematic and much experimenting may be needed.

Hand-Held Magnifiers

The hand-held magnifier is especially useful for shorter-term reading, such as looking up words in a dictionary or telephone book, or reading bills and recipes.

The advantages of a hand-held magnifier are:

• It is usually inexpensive, portable, and readily available.
• You are probably familiar with magnifiers already.
• Most magnifiers are available in a variety of shapes and sizes.
• Magnifiers have the most "normal" appearance of any low vision device.
• You can vary the distance at which you hold the magnifier from your eyes, depending upon your reading needs.
• Some magnifiers come with built-in lights.

The disadvantages of a hand-held magnifier are:

• It requires steady hands and good control.
• Higher power (or stronger) magnifiers allow you to read only a few letters at a time.
• Your reading speed will probably decrease.
• Magnifiers without built-in lights require supplemental lighting for best vision.
• Finding and maintaining the correct focus is sometimes difficult.

Magnifying Reading Glasses

Magnifying reading glasses allow an individual to read for extended periods of time.
The advantages of magnifying reading glasses are:

• You are probably familiar with reading glasses already.
• You can read several words at one time.
• You can keep both hands free, unlike using a hand-held magnifier.
• You can read with both eyes if your prescription is a lower-powered one.
• They can be useful for avid readers.

The disadvantages of magnifying reading glasses are:

• A higher magnification power can require a very close reading distance, which can be tiring and frustrating for some individuals.
• Training is sometimes required in order to use magnifying reading glasses effectively.
• Finding and maintaining the correct focus can be difficult and require practice and experimentation.
• Your neck, arm and shoulder muscles can become fatigued if you read for a long time.
• It's possible to experience eyestrain and headaches initially.
• It's important to experiment with selecting and positioning appropriate lighting.

Distance Devices

"Distance" devices are best for activities such as television viewing, a visit to the movies/theater, attending a sporting event, and bird watching. The most common type of distance optical device is the hand-held telescope.

The advantages of hand-held telescopes are:

• They are inexpensive, small, and portable.

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Find the Little Mak Hand-held Telescope shown here at Edmund Scientifics web site.

The disadvantages of hand-held telescopes are:

• They provide a very limited field of vision.
• You cannot walk or move about when looking through the telescope, because you can easily trip and fall if you do so.
• They require steady hands and good control in order to focus the lens.
• Even slight hand movements or tremors can affect the clearness of the image.

Combination Devices: Telemicroscopes

Telemicroscopes combine "near" and "distance" devices for activities performed beyond arm's length. They can also be beneficial for closer activities, such as playing cards, making crafts, playing bingo, and preparing meals. As the name suggests, telemicroscopes combine the characteristics of telescopes (an extended viewing distance) and reading glasses (magnification).

The advantages of telemicroscopes are:

• You are able to see at an intermediate distance because they provide a good level of magnification at arm's length.

Find the Zeuss G1 telemicroscope shown in the photo at EyeAssociates.com web site [link opens in new window]

The disadvantages of telemicroscopes are:

• They can feel heavy on your face.
• They are the least "normal" looking of any low vision device.
• It can sometimes be difficult to find and maintain the correct focus.
• Your depth perception and balance can be affected because objects appear closer than they really are.
• You cannot walk or move about when using telemicroscopes, because you can easily trip and fall if you do so.

It's important to remember that the benefits of optical devices can be enhanced by combining them with non-optical devices (such as lighting), to increase illumination and contrast and reduce glare.