What Are Low Vision Optical Devices?
What Are Low Vision Optical Devices? The Low Vision Specialist "Near" Optical Devices Tips for Using Magnifiers and Magnifying Reading Glasses "Distance" Optical Devices Increasing the Benefits of Low Vision Optical Devices
What Are Low Vision Optical Devices?
Low vision optical devices include a variety of devices, such as stand and hand-held magnifiers, strong magnifying reading glasses, loupes, and small telescopes. Because these devices can provide greatly increased magnification powers and prescription strengths, along with higher-quality optics (i.e., the way the lens bends or refracts light), they are different from regular glasses and commercially available magnifiers.
Low vision optical devices are task-specific. You can think of them as being similar to "tools" that are used to build a house—different tools for different tasks. Therefore, your eye doctor may prescribe several different low vision optical devices for various tasks: One or two devices for reading, another for watching television and seeing faces, another for seeing the computer screen, and yet another for sewing. Your doctor may also recommend sunglasses to reduce glare, protect your eyes from ultraviolet (UV) and blue light, and enhance your ability to see more clearly in different lighting conditions.
If you have low vision, your standard prescription eyeglasses are usually no longer sufficient to help with distance and near tasks. In addition, you may need several different optical devices to help with a variety of everyday tasks you want to do.
You may find that using low vision optical devices effectively is different from what you have been used to in the past, when a single pair of glasses did everything—helping you to see at distance, intermediate, and up close. Many persons with low vision can have 4-5 different devices to help with a range of everyday tasks.
The Low Vision Specialist
It's recommended that you see an eye doctor who is a low vision specialist to determine the right types of devices that will help you with the everyday tasks you want to perform. Some doctors may recommend starting with one or two devices to see how you manage, and then adding additional devices as you become used to working with the devices you have.
It is extremely helpful to both you and your doctor if you can make a list of the tasks or activities that are most important to you and share that information with him or her when you have a low vision eye exam. It's also helpful to bring along samples of your everyday tasks, such as mail, bills, or needlework.
The low vision service is incomplete unless you've been taught how to use the devices that have been prescribed for you. After you've been prescribed low vision devices, such as a magnifier or telescopic glasses, it's important to learn how to use them when you get home.
Before any optical or non-optical device can be effective and comfortable, you will need to:
Be motivated to use the device for specific tasks
Be confident that the device has been appropriately prescribed
Understand how to maximize the use of the device
Understand the potential and limitations of the device.
Low vision optical devices can be grouped into two basic categories:
"Near" optical devices for close-up, detailed viewing activities, such as reading, writing, sewing, and crafting
"Distance" optical devices for spot (or short-term) viewing and for activities that are farther away, or beyond arm's reach, such as reading street signs and aisle numbers; identifying numbers on buses and trains; seeing television and faces better; and viewing movies, sporting events, and scenery.
"Near" Optical Devices
"Near" optical devices are used for close-up, detail viewing, such as reading, writing, and sewing. The most common devices in this category include:
The simplest device for reading is the stand magnifier. When placed on the page, this type of magnifier is automatically in focus for reading.
A stand magnifier with a handle
Some advantages of stand magnifiers are:
They rest flat on the page, and do not need to be held above the page. Therefore, they are not tiring to hold above the page or frustrating to hold steady, like a hand-held magnifier may be.
The focusing distance is set by simply placing the magnifier on the page.
They are helpful for longer reading periods, and for reading at home.
Most stand magnifiers now come with built-in lights that provide excellent illumination.
They are fairly inexpensive and easy to use.
They can be used in combination with regular eyeglasses and bifocals.
Some disadvantages of stand magnifiers are:
Reading with a lighted stand magnifier
They are larger and perhaps bulkier than a hand-held magnifier; therefore, they are not as portable, and may not fit in your pocket or purse to take to a store or restaurant.
If you do not get fairly close to the lens, you may see a relatively small field of view; therefore, it can be helpful to use a reading stand (explained below) to help you get closer to the lens. Otherwise, you will have to bend over to read, which can be tiring.
If the stand magnifier does not have a built-in light, it may cast a shadow or cause reflections on the page that make it difficult to read print.
A hand-held magnifier is especially useful for brief "spot" reading and for portable use, such as reading a menu in a restaurant, prices or labels in a store, or appliance dials at home. They can either be full size or a small pocket magnifier, and can also have a built-in bright light.
A hand-held lighted magnifier
Some advantages of hand-held magnifiers are:
Many people are already accustomed to using one, or can learn to use one easily.
They are portable and easy to take to a restaurant, store, or church.
They are relatively inexpensive.
If they have a light, it can provide helpful illumination, such as when reading a menu in a darker restaurant.
They are available in a variety of magnification strengths, sizes, and shapes.
Some disadvantages of hand-held magnifiers are:
Reading prices with a hand-held magnifier
They are tiring to hold and are not intended for long reading periods, such as sitting down to read the newspaper, a magazine, or a book.
They may be frustrating to hold steady, and to find and maintain the correct focal distance, or focus.
They require steady hands and good motor control.
If the magnifier does not have a built-in light, it may cast a shadow or catch reflections from the light, which can make it difficult to read print.
If you don't hold the magnifier close to your eye, you may have a small field of view, and only see a few words or letters at a time.
Magnifying Reading Glasses
Magnifying reading glasses allow an individual to read for longer periods of time. They are also called "microscopes" because they produce magnified images of small words and objects.
Magnifying reading glasses
Some advantages of magnifying reading glasses are:
They help provide a wide field of view, so you can read a fair amount of a line at a time.
They are portable, allowing you to read or do hand work almost anywhere.
Your hands are free—not needing to hold a magnifier.
Because you are hands are free, they may be helpful when reading the computer screen, sheet music, or doing hand work.
With lower powered magnifying reading glasses, you may be able to use both eyes.
Some disadvantages of magnifying reading glasses are:
Reading with magnifying reading glasses
They require you to hold things very close – both reading materials and hand work.
Because you need to hold things very close, they may block out available light. Most persons with low vision need good illumination, so use of strong reading glasses may complicate this.
You need to hold print (or other materials) very steady. This can be frustrating, especially if a book is heavy, if you are reading for a long period of time, or if your hands shake.
If you are very nearsighted (myopic) and/or have a high amount of astigmatism, you may not like strong reading glasses or do well with them.
Holding things close and correct use of the strong reading glasses usually requires training to use them successfully, and practice to keep things in good focus.
Loupes are magnifying devices. A clip-on loupe attaches to glasses, and allows a person to be hands free while viewing text, the computer screen, sheet music, or hand work. Stronger loupes (over +10D, or diopters) can be used only with one eye, whereas weaker loupes can be used for both eyes.
A clip-on loupe
Some advantages of clip-on loupes are:
They allow the person to retain their correction from their prescription glasses while using them. This is especially helpful if the person has strong myopia (nearsightedness) or astigmatism.
Your hands are free—not needing to hold a magnifier.
They are convenient and easy to use—flip them up when not using them, bring them down in front of your glasses when you are using them.
They are inexpensive.
Some disadvantages of clip-on loupes are:
Reading with a loupe
For larger loupes (used for persons with larger glasses), they may be a bit heavy, and may even cause the glasses to slip down on your nose.
If the loupe has a bar attaching it to the clip, and the loupe rests a couple inches in front of the glasses, some persons may feel that the bar is distracting.
Some persons may also notice that the field of view is somewhat small through the loupe, which can make reading more difficult.
Stronger loupes may require that you use only one eye for reading.
Telemicroscopic glasses are telescopes that are adapted and made for tasks at near, rather than at distance, like most telescopes. They are available in many different designs. Telemicroscopic glasses, in contrast to strong magnifying reading glasses, allow a more comfortable working distance when reading, using the computer, seeing sheet music, doing hand work, playing cards, and other tasks.
Some advantages of telemicroscopic glasses are:
They provide a more comfortable working distance than magnifying reading glasses or clip-on loupes.
Your hands are free—not needing to hold a magnifier.
They usually have excellent optics, and provide an image that is very crisp.
Some disadvantages of telemicroscopic glasses are:
Reading with telemicroscopic glasses
They provide a smaller field of view, which can be frustrating.
You need to hold print (or other materials) very steady. This can make reading difficult, especially if a book is heavy, if you are reading for a long period of time, or if your hands shake.
The image may be somewhat dark.
Telemicroscopes have the least "mainstream" appearance of all "near" low vision optical devices. This aspect of low vision optical devices is important for some individuals and can be a consideration when selecting a device that you are comfortable using.
They can feel heavy on your nose and face.
They can be quite expensive.
Why Can't I Find a Low Vision Optical Device that Can Make the Print Larger AND Allow Me to See the Entire Page?
Some thoughts from Audrey Demmitt, RN, BSN, and a VisionAware Peer Advisor
It's important to have the right magnification strength prescribed for you. Too much or too little magnification won't work well, and this can happen if you are just guessing at the magnification power you need. As your need for magnification increases, the size of the magnifier lens (or the viewing area) will become smaller. This is the science of optics and magnification: the stronger the power, the smaller the lens will have to be.
My clients often do not understand this and state that they want both a large viewing area and strong magnification. I wish it was possible to have a magnifier with a very large lens and very strong allover magnification — but it is not. There just isn't a magnifying device available that will do that optically and provide any degree of magnification — with the exception of an electronic video magnifier.
I always try to advise people to start by having a low vision evaluation and learn the particulars of their eye condition before they try to purchase low vision devices on their own. Why purchase a variety of over-the-counter or mail-order devices that don't work? In the long run, going to a low vision specialist can save you money, time, and much frustration.
Tips for Using Magnifiers and Magnifying Reading Glasses
You may notice some difference at first when you begin to use your low vision devices at home. It may be different from what you remember it was like during your low vision examination. Many people have this experience and sometimes believe that the doctor or low vision specialist sent them home with the wrong magnifier or reading glasses.
It's also important to realize that it often takes time, patience, practice, and much encouragement and support to learn how to use all types of low vision optical devices successfully. Family and friends can play an important role in encouraging you to be patient and to keep trying. They can also help you experiment with lighting, including different types and positioning, and to use the devices correctly, as you were trained to do with the low vision specialist.
Remember that the lighting and reading conditions in your home are very different from those in a specially designed low vision clinic or office.
Try to be patient with yourself when learning to use the device prescribed for you. Like any other skill, learning to read with a low vision device requires regular practice over many weeks.
You'll probably have to get used to holding the reading material much closer to your eyes than before. Reading at this very close distance may be uncomfortable at first, but it won't hurt your eyes or cause your vision problem to become worse.
When using a stand or hand-held magnifier, the closer the lens is to your eye, the more of the line you will see. This will also help you increase your reading speed, your comprehension, and your enjoyment in reading, and will decrease frustration.
Use a reading stand or clipboard to hold your reading and writing materials. This will help bring the material closer to your eye, which results in achieving a larger field of view. It will also help enlarge or magnify the print, as you bring things closer. And it helps with better posture, as well as minimizing blocking out the light, since you will not be bending over the materials as much.
Remember that you'll need much more light than before.
Use a gooseneck or flex-arm lamp to bring the light closer to the material you're reading. A regular ceiling light or room lamp usually isn't enough.
Position the light so that it's on same side as the eye you're using to read. Also, try not to position the light directly in front of you, shining into your eyes.
If you’re having trouble keeping your place on the line, or even finding where to look on the page, use a typoscope to track along the line, follow, and come back to the next line. A typoscope is a piece of durable black plastic with a cutout opening that can help you focus on the line you are reading.
You can learn more about all of these options at Helpful Non-Optical Devices for Low Vision on this website.
"Distance" Optical Devices
"Distance" optical devices can either be hand-held, clip-on, or mounted in a frame to be hands-free. They can be used for brief spot-reading tasks, such as reading a sign, menu board, or the white board in school. They can also be used for longer viewing periods, such as watching television, seeing a movie or ball game, viewing a play or program, and enjoying scenery.
A hand-held telescope is called a telescopic "monocular," because it is used with one eye and has a single eyepiece. Generally, it is used for short viewing periods, such as reading a street sign, house number, menu board in the restaurant, aisle number in the grocery store, or white board in school. Some people may also use it for tasks that are fairly close, such as reading the bathroom scale, or a price on a shelf in the grocery store.
A hand-held telescope
Some advantages of hand-held telescopes are:
They can be very helpful for viewing a wide range of items at distance, and even some things fairly close up.
They are fairly inexpensive and are portable.
They are available in a range of magnification powers.
They can be kept on a cord around your neck, in a pocket, or purse, for use when desired for "spot" viewing, such as reading street signs outdoors or aisle numbers in a store.
Some disadvantages of hand-held telescopes are:
A clip-on telescope
They may provide a limited field of view, which can be frustrating.
The image you see may be fairly dark, and many persons with low vision need good illumination.
Depth perception is distorted and balance may be affected if you walk or move about while looking through a monocular, so it is not recommended.
They require good motor control in order to focus the lens, and to be steady to keep it in focus. Even slight hand movements or tremors can affect the clearness of the image.
Please note: Monocular telescopes also come in clip-on versions (pictured at left) that attach to eyeglass frames and leave both hands free. This hybrid telescope can be used with one eye for longer periods of time, such as viewing a PowerPoint presentation, or watching television.
Spectacle-mounted telescopes are permanently attached to the lens of your eyeglasses.
Wearing spectacle- mounted telescopes
Some advantages of spectacle-mounted telescopes are:
They leave both hands free, as opposed a monocular telescope.
Therefore, they can be used for longer viewing periods, like viewing television, a program, ball game, or movie, as opposed to a monocular, which can be tiring to hold and difficult to hold steady.
They appear to bring things closer and magnify things nicely.
They can be binocular (for both eyes) or monocular (for one eye).
They are available in a range of magnification powers.
Some disadvantages of spectacle-mounted telescopes are:
One type of spectacle- mounted telescopes
They provide a smaller field of view than if viewing items without telescopic glasses.
Some persons with severe arthritis, poor motor control, or tremors may have difficulty focusing the lenses.
Because depth perception is distorted and balance is affected while looking through the telescopic lenses, walking or moving about is not recommended while wearing spectacle-mounted telescopes.
Spectacle-mounted telescopes have the least "mainstream" appearance of all "distance" low vision optical devices. This aspect of low vision optical devices is important for some individuals and can be a consideration when selecting a device that you are comfortable using.
Bioptic telescopic glasses are a type of spectacle-mounted telescopic glasses. They are mounted in the upper part of eyeglass lenses.
Bioptic telescopes in place on eyeglass lenses
This placement allows the user to look through the bottom half of the lens while seeing most items at distance, and looking through the telescopes at the top of the glasses to see a magnified image.
Some states, under strictly specified conditions, allow some persons with low vision to use bioptic telescopes for driving.
In states where this is not legal, some persons with low vision use bioptic telescopes for reading, doing hand work, or other tasks.
You can learn more about driving with bioptic telescopes, including resources and driving alternatives for adults, at Driving with Low Visionon this website.
Increasing the Benefits of Low Vision Optical Devices
In addition, it's important to know that the benefits of low vision optical devices can be enhanced by combining them with reading stands, yellow filters, typoscopes, proper lighting, and table or floor lamps. You can learn more about these options at Helpful Non-Optical Devices for Low Vision on this website.
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