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. Assistive technology is an interdisciplinary field of knowledge comprising products, resources, methodologies, strategies, practices, and services that promote functionality for visually impaired people with regard to autonomy, quality of life, and social inclusion. It can be used with other methods of magnification, requiring a lower final power for the chosen optical aid. Includes case and chain. Spectacle-mounted telescopes are permanently attached to the lens of your eyeglasses. When placed on the page, this type of magnifier is automatically in focus for reading. Handheld magnifier with 2.5x magnification, 2.25" diameter glass lens and a built-in 8 bright LEDs plus 1 UV blue light. They can be very helpful for viewing a wide range of items at distance, and even some things fairly close up. Fixed optical center makes adaptation on eccentric vision difficult. Most stand magnifiers now come with built-in lights that provide excellent illumination. A typoscope, caps or visors, side shields, and/or polarizing lenses should be prescribed to control the reflection of light. You can think of them as being similar to tools that are used to build a housedifferent tools for different tasks. It is the aid of choice for patients who cannot hold a lens or tolerate the distance of microscopes. It is available for far, near, and middle distances (Figure1). Pocket-sized handheld magnifier. Stand magnifiers are convex (plus) lenses designed with a rigid mounting placed close to the object (Figure3). (Figure7). Includes a neck cord, lens cloth and a carry case. They are helpful for longer reading periods, and for reading at home. High-plus spectacles working distance. Its 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. 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. MoJo Lens measures 1.4 inches. When and if this becomes an issue, near aids can be beneficial. Using Low Vision Effectively. Hyvarinen L, Jacob N. What and How Does this Child See? These disadvantages restrict its use in children or in patients with poor motor coordination. Reizen Maxi-Brite LED Handheld Magnifiers A pair of hands-free binoculars designed for distance viewing that are worn like eyeglasses. Compact and lightweight illuminated pocket magnifier with distortion-free bi-aspheric lenses. Light Gathering Dome Magnifiers Features a nearly 3/4" diameter color-corrected triplet lens in a sturdy metal body. Roadmap to Living with Vision Loss: What Kinds of Services Will You Need to Maintain Independence? The telescope can be prescribed for reading blackboards, and later, to use more constantly at far. A low vision specialist may prescribe several different low vision optical devices for various tasks or help determine the right type of device or devices that will help a user with the tasks her or she wants to perform. Fluorescent light emphasizes the "cooler" blue spectrum, which can intensify glare. Telescope systems for near, or telemicroscopes, are distance telescopes that can be focused from infinity to near range or that can be modified by putting a reading cap over a distance unit (Figure2). They are available in many different designs. They may provide a limited field of view, which can be frustrating. Magnifying devices are generally either handheld or mounted on a stand, with zoom ranges from 2x to 10x. Ed. Determine the VA that the patient requires. 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. Hand-held magnifiers provide maximum magnification when an object is standing at or close to its focal distance, producing parallel rays and the image forming at infinity optically (Figure5). High-powered, long-life LED light bulb has a projected lifespan of 10,000 hours. By Bryan Gerritsen, M.A., CLVT Edited by Maureen A. Duffy, M.S., CVRT, What Are Low Vision Optical Devices? Requires three AAA batteries (not included). It is also important to support daily activities with aids such as black felt-tipped pen, bold lines, and contrasting colors. Sports glasses that are ideal spectacles/binoculars for distance viewing for TV, the movies, ballet and sporting events. The protective case doubles as a handle. 174. Reizen 3.5x Illuminated Pocket Magnifier Tungsten bulbs provide evenly distributed light. A 2x lens framed by a rubber frame and flexible band that fits around just about any size cell phone and even portable phones. Hand-held magnifier at appropriate working distance. Dome magnifier with a 60mm glass lens with 5x magnification. They allow the person to retain their correction from their prescription glasses while using them. These models include an eye cup, neck strap, and protective case. Monocular with Cord They rest flat on the page, and do not need to be held above the page. Some advantages of hand-held telescopes are: Some disadvantages of hand-held telescopes are: Please note: Monocular telescopes also come in clip-on versions (pictured at left) that attach to eyeglass frames and leave both hands free. Clamps fit up to 2.5 thickness. Comfortable and lightweight binoculars with each lens able to be focused individually. It is especially useful for preschool children or a child in the early stages of training with low-vision aids. (50mm x 75mm). It is important to let the child experiment with the TS in different situations. Clinical Low Vision. It is particularly indicated for short activities and could be a first prescription choice for children (Figure2). The telescopic system (TS) or telescope is an optical instrument that improves the resolution of an object by increasing the size of the image projected on the retina, making it closer. Shadow highlighting makes details of uneven surfaces pop-out to the viewer and is well suited for many inspection tasks. Boston/Toronto: Little, Brown, and Company. Comes with a black plastic carrying case. Most of our funding comes from individuals, not corporate sponsors. Dome Magnifier In states where this is not legal, some persons with low vision use bioptic telescopes for reading, doing hand work, or other tasks. Try to be patient with yourself when learning to use the device prescribed for you. Determine the best corrected VA for near/distance. They are fairly inexpensive and easy to use. 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. It's lighter, shorter, and cheaper than the Keplerian type, thus the first-choice prescription for children. VES Sports Low-vision devices are designed to improve visual performance in children with low vision, thus enabling academic and social adaptation and providing enrichment of daily experiences.1,2 They can be optical or optical and electronic. Orientation and mobility techniques should be encouraged at all low vision levels. Light source is located behind the magnifying lens, casting the light at an angle of incidence ideal for highlighting object details. Adjustable focus monocular with a detachable woven 33" neck strap, a soft fabric cleaning cloth and a protective vinyl carry case. To achieve better acceptance of any aid, consider the child's needs, goals, and ability to handle the aid, as well as the esthetics, weight, cost, and timing of the prescription. High-power illuminated aspheric lens stand magnifier with scratch-resistant coating and an interchangeable head that allows users to change the magnifier. Large 10" x 12" magnifier for reading newspapers, books, or magazines. Reserved. They can be binocular (for both eyes) or monocular (for one eye). Empowering people toward greater independence and lifelong success by providing curated information and resources to assist children, parents, job seekers, adults, and older people who are blind or visually impaired. A binocular prescription might be possible for adds more than 12D. However, the reduction of visual field, lighting, depth of focus, weight, and aesthetics restrict the acceptance by a child.14, Nonoptical aids are visual aids that do not use magnifying lenses to improve visual function.2 They can improve the other visual aid's function or can even replace optical aids. Pocket-sized illuminated magnifier with all the features of handheld models. Sight-enhancing, clinically validated electronic glasses for reading, travelling safely, and engaging in various activities. x 1.9 in. My clients often do not understand this and state that they want both a large viewing area and strong magnification. Different electronic devices are currently available: A video magnifier system consists of a monitor and a camera that projects the enlarged image on the screen. Use a gooseneck or flex-arm lamp to bring the light closer to the material youre reading. Handheld illuminated pocket magnifier with a bright, cool, LED light that illuminates evenly with no glare. The visual field (VF) has a great influence on the telescope adaptation. Includes protective soft cloth pouch. They are available in a variety of magnification strengths, sizes, and shapes. Because you need to hold things very close, they may block out available light. 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. Diseases such as aniridia, achromatopsia, and albinism require low-level lighting; glaucoma, retinitis pigmentosa, optic atrophy, and nuclear cataract require high illumination. May be worn over eyeglasses or alone. For more information about helpful lighting for reading, you can view Positioning a Light Source and Minimizing Glare in the VisionAware Better Lighting for Better Sight video series. Relative size or linear magnification is magnification brought about by enlarging the object itself. If you have low vision, your standard prescription eyeglasses are usually no longer sufficient to help with distance and near tasks. When using natural light, the child should sit with their back to the window or on the side leading to the best lighting and visualization. Natural light is the adequate lighting for most low-vision children; however, artificial light allows better control of illumination. 55mm dome magnifier with a non-scratch base with a 4x magnification. It provides a smaller visual field when compared to a microscope and requires good hand-eye coordination. Copyright 2021 American Printing House for the Blind. The larger working distance makes it easy to use for writing, drawing, or painting. Electronic devices can be very helpful in moderately or severely visually impaired children and in children who do not respond to other proposed aid. It can be fixed or portable, black and white or color, mouse or tray, and fixed-focus or autofocus, allowing objects to be seen at various distances (Figure9). The Galilean telescope is a simple system consisting of 2 lenses: The distance between the 2 lenses is determined by the difference in their focal lengths. 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. They require good motor control in order to focus the lens, and to be steady to keep it in focus. Handmade dome magnifier with a base made of oak ideal for viewing larger area. Uses a high-definition camera and a powerful algorithm processes the video and displays it onto near-to-eye screens with no perceptible delay. 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. They are also called microscopes because they produce magnified images of small words and objects. 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. Stand magnifier: Divergent rays come from the lens. Lighting necessity varies for every individual and depends on the diagnosis and extent of pathology. Handmade dome magnifier with a walnut base ideal for viewing larger areas. Comes with a protective pouch. Extra Large Dome Magnifier High-quality standard aspheric lenses that result in excellent distortion-free images. In: Fletcher DC. Absorptive lenses in yellow for low-light environments and amber for more intense lighting are good prescription options. The distance between the lenses is the sum of their focal lengths. It may be different from what you remember it was like during your low vision examination. Figure 2. Advantages are higher reading speed (2.5times) and greater working distance (3times) when compared to other aids. Low vision optical devices are task-specific. You can learn more about these options at Helpful Non-Optical Devices for Low Vision on this website. Why purchase a variety of over-the-counter or mail-order devices that dont work? A computer and a tablet can be a good option for a multihandicapped child. 1984. The focus should be placed at shoulder height corresponding to the better-seeing eye, forming a 45degree angle with the visual axis. Reizen Sport Glasses 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. There just isnt a magnifying device available that will do that optically and provide any degree of magnification with the exception of an electronic video magnifier. Helsinki, Finland: Vistest Ltd. 2011. All Rights The distance between the observer and the magnifier can vary; the higher the distance, the smaller the visual field will be. It is important for the child to be comfortable with the aid proposed. Foldout Lighted Stand Magnifier Comes with a protective leather pouch. Includes pouch and neck cord. It is mobile, hands free, and suitable for near, far, and mid-range tasks. Bright field dome magnifier with a 95mm acrylic lens that provides a large viewing surface for maximum light-collecting effects. The dome design allows a magnified view from multiple angles. VA directly influences the successful rehabilitation with optical aids. The 2x Fresnel magnifier lens is made of optical-grade acrylic which will not bend or distort words or images. Large print permits unrestricted fields of view and allow more normal working distances and greater speed of reading than optical aids. High-plus spectacles are convex (plus) lenses mounted in a spectacle frame (Figure3). The type, position, and intensity of the light source should be monitored. eSight can be used in place of other low vision tools, such as CCTVs, digital magnifiers, and screen-reading technology. They can be used for brief spot-reading tasks, such as reading a sign, menu board, or the white board in school. This hybrid telescope can be used with one eye for longer periods of time, such as viewing a PowerPoint presentation, or watching television. Available in clear, blue, bright yellow and pink. The distance of the hand magnifier away from the object needs to be at the focal length, to supply maximum magnification. Low vision optical devices are task-specific. Watson GR. diameter. It is more discreet, lighter, and cheaper. 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. 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. 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. Uses two AA batteries (not included). 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. From this stage, a stand magnifier or a hand magnifier can be used for reading small-print books such as dictionaries (Figure10). However, as school activities get more sophisticated and the fonts of reading material get smaller, greater magnification is required and objects are brought too close, making reading more fatiguing. For eccentric viewing educational training of the TS must be performed before prescription. E-mail: They provide a smaller field of view than if viewing items without telescopic glasses. Features glare-reducing soft rubber eye shields. 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. Bioptic telescope that can be mounted onto specially designed eyeglass frames and can incorporate normal distance prescription and bifocals. They are fairly inexpensive and are portable. Uses two AA batteries (not included). 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. 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. Monocular that magnifies objects 10x with 25mm (0.98 inch) lens. If you dont 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. This is especially helpful if the person has. Coil Raylite Illuminated Stand Magnifiers Incandescent Raylite Magnifiers Even slight hand movements or tremors can affect the clearness of the image. May also be used as a hands-free magnifier that can be hung around the neck for working on crafts and hobbies. They may be frustrating to hold steady, and to find and maintain the correct focal distance, or focus. The light should be shone directly on the reading material, avoiding reflective surfaces. The patient will have difficulty localizing and tracking objects when there is a central or paracentral scotoma with normal peripheral vision or scotomas above the fixation area. Hand-held magnifiers are either convex (plus), convex sphere, or aspheric lenses with a handle that allows them to be held in various positions (Figure3). Features an easy access battery compartment for when you need to change the two AA batteries (not included). Good coordination and training are essential.13. 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. Figure 4. Ecolux 8x/28D LED Handheld Illuminated Magnifier Measures less than six inches in length and comes in its own soft vinyl drawstring carry case and storage/gift box. Fixed focus, focusable telescope, or autofocus, Objective lens: convex (plus) lens, closest to the object, Ocular lens: minus lens, closest to the eye, Telescope system for near (telemicroscope), Can be prescribed binocularly by adding up to 10 diopters. 3.25x Auto Touch Handheld Magnifier Reduces visual field in high-power lenses and obstructs light at closer distances. Optivisor Binocular Magnifiers However, they both weigh and cost more. It is useful for prolonged activities and activities that require visualization of details. The device can be illuminated. 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. They provide a smaller field of view, which can be frustrating. These handheld telescopes are usually small enough to fit in the user's pocket. They provide maximum magnification when objects are positioned at or near the focal distance of the lens, producing parallel rays and the image forming at optical infinity (Figure4).2,3. The magnifier measures 3 1/2" x 1 1/2" when opened, and 1 1/2" x 2" when closed. Illuminated stand magnifier for viewing reading materials on a flat surface. The user rests and slides the dome magnifier across the reading material thus eliminating fatigue while reading. Rays emerging from the stand are not parallel, but divergent, requiring accommodative effort or a moderate reading aid to bring the image into focus (Figure6).2 The device can be illuminated. Acrylic Full-Page Magnifier Sterns GK, Hyvarinen L. Adressing Pediatric Issues. The most common devices in this category include: The simplest device for reading is the stand magnifier. Flip Down Magnifying Glasses The image is real and inverted, requiring a prism to reverse the image, making it longer and heavier. 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. 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. Reizen 5x Dome Magnifier with Glass Lens 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. It is important to consider comfort; protection from ultraviolet, infrared, and visible light; increased contrast; and glare reduction. Pocket magnifier with a 5x aspheric lens that slides in and out of a hard-plastic case. 2a. With its large field of view, it may be used for reading price tags, menus, mail, newspapers, street signs and viewing the beauty of nature. When conventional lenses do not provide required visual range, aids that have optical properties capable of promoting better visual performance through lenses are indicated.2. Uses three AAA batteries (not included) that last approximately 100 hours. Like any other skill, learning to read with a low vision device requires regular practice over many weeks. Figure 5. In cases of low contrast, adaptation to the device can also be more difficult. 5x Two Lens Unisex Magnifier They are portable, allowing you to read or do hand work almost anywhere. Position the light so that its on same side as the eye youre using to read. Magnifying lamp with a flexible gooseneck arm and limitless positioning options. The clip-on model has the advantages of both: It is lighter than the spectacle-mounted model, however, it can scratch the lenses and reduce the visual field to further distances. In: Fletcher DC. The patient should be monitored frequently to evaluate the effective use of the aid prescribed and difficulties presented in daily activities and to set up more advanced goals. Comes with a protective pouch. Copyright 2020 American Foundation for the Blind Privacy Policy Sports Spectacles A fixed-focus telescope is indicated for children with poor motor coordination. When using a stand or hand-held magnifier, the closer the lens is to your eye, the more of the line you will see. A regular ceiling light or room lamp usually isnt enough. Different filters can be prescribed for different situations, paying close attention to the goals to be achieved, levels of lighting, cost, and especially the individual preference. Handheld monoculars that have dual purpose scopes, which work well for both near and distance viewing. 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. Stronger loupes (over +10D, or diopters) can be used only with one eye, whereas weaker loupes can be used for both eyes. High-tech aids are increasingly of benefit to people with low vision. The image you see may be fairly dark, and many persons with low vision need good illumination. Coil 2x Binocular System Eyeglasses with flipdown magnifying lenses with 1.75x magnification. Because of the fixed focus, stand magnifiers work well for children. In low-vision daily practice, it is common for a child to have more than one aid.5. For those with concentric VF loss, mainly for VF less than 5 degrees, aids should be prescribed with caution. You can learn more about all of these options at. Magnifiers slide into a hard cover case that has a black cord to hang around one's neck. Enhancing Impaired Vision. Comes with a soft nylon cord securely attached to the magnifier. Full-page magnifier that provides 2x-3x magnification with a 2mm-thick Fresnel lens. Some advantages of hand-held magnifiers are: Some disadvantages of hand-held magnifiers are: Magnifying reading glasses allow an individual to read for longer periods of time. You may notice some difference at first when you begin to use your low vision devices at home. They can either be full size or a small pocket magnifier, and can also have a built-in bright light. Full-page Fresnel magnifier ideal for looking at small print in phone books, reading instructions and maps or doing hobby work. Comes with a neck chain and carrying case. Binocular telescope is indicated when there is similar VA in both eyes, with the purpose of increasing the visual field, and for nystagmus. Low vision optical devices include a variety of devices, such as stand and hand-held magnifiers, strong magnifying reading glasses, loupes, and small telescopes. They should filter ultraviolet radiation below 400nm, minimizing the loss of VA and color discrimination. Some persons with severe arthritis, poor motor control, or tremors may have difficulty focusing the lenses. They provide a more comfortable working distance than magnifying reading glasses or clip-on loupes. Features a plastic frame available with focusable 2.8x, 2.8x, or 2.5x magnification. In addition, its 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. Your hands are freenot needing to hold a magnifier. 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. Understand the potential and limitations of the device. However, few books are available in large print, they are more expensive, and they are larger and heavier than standard print, sometimes expanding from a single volume to multiple. Distance optical devices can either be hand-held, clip-on, or mounted in a frame to be hands-free. The autofocus telescope both weighs and costs more and it does not constitute the first choice prescription for children. Uses three AAA batteries (not included). Requires batteries (not included). Magnifier features 5-diopter glass lens that is five inches in diameter with 2.25x magnification when held at a distance of 5-8 below the lens. It allows magnification of 2to60times and binocular vision. When a TS is first prescribed, a manual, monocular telescope with lower magnification is recommended (Figure11). If the VA is less than 20/400 and the central scotoma greater than 30degrees, a video magnifier is indicated. If youre 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. Large visual-field defects (less than 5degrees), VA less than or equal to 20/800 or better than 20/800, Increased adaptation to the daily activities materials. Many people are already accustomed to using one, or can learn to use one easily. Lighting control is of great importance to enhance contrast and reduce glare. Some advantages of spectacle-mounted telescopes are: Some disadvantages of spectacle-mounted telescopes are: Bioptic telescopic glasses are a type of spectacle-mounted telescopic glasses.