| Many patients classified as blind today actually have | | | | history. In addition, the optometrist will discuss the |
| some sight remaining and, thanks to developments in | | | | functional problems with the patient, including such |
| the field of rehabilitative vision, also known as low | | | | things as reading, functioning in the kitchen, glare |
| vision, they can be helped to make good use of it. | | | | problems, travel vision, the workplace, television |
| Anyone with reduced vision is visually impaired, and | | | | viewing, school requirements, and hobbies and |
| can have problems functioning, ranging from minor to | | | | interests. |
| severe difficulty. There are two general classifications | | | | Preliminary tests may include assessment of ocular |
| of low vision in use today:o partially sighted - visual | | | | functions such as depth perception, color vision, |
| acuity that with conventional prescription lenses is still | | | | contrast sensitivity, and curvature of the front of the |
| between 20/70 and 20/200 (a person with 20/70 | | | | eye. Measurements will be taken of the person's visual |
| eyesight must be 20 feet away to see clearly an | | | | acuity using special low vision test charts, which include |
| object that a person with 20/20 eyesight can see | | | | a larger range of letters to more accurately determine |
| clearly from 70 feet away);o legal blindness - visual | | | | a starting point for gauging low vision. Visual fields are |
| acuity that cannot be corrected to better than 20/200 | | | | usually evaluated, and each eye will be examined. |
| with conventional lenses and/or the patient has a | | | | The optometrist may prescribe various treatment |
| restricted field of vision less that 20 degrees wide. | | | | options, including low vision devices, as well as assist |
| (Note that some definitions of "partially sighted" include | | | | the person with identifying other resources for vision |
| the legally blind.) | | | | and lifestyle rehabilitation. |
| Low vision impairments take many forms and exist in | | | | There is a wide variety of optical devices and |
| varying degrees. It is important to understand that the | | | | adaptive products available to help people with low |
| visual acuity alone is not a good predictor of the | | | | vision live and/or work more productively and safely. |
| degree of the problem a person is having. Someone | | | | Most people can be helped with one or more of them. |
| with relatively good acuity (e.g., 20/40) can be having a | | | | Unfortunately, only about 20-25 percent of those who |
| very hard time functioning, while someone with worse | | | | could benefit have been seen by a low vision specialist |
| acuity (e.g., 20/200) might not be having any real | | | | and had treatment options, including low vision devices, |
| problems doing the things that they want to do. | | | | prescribed specifically for them. The more commonly |
| The common types of low vision are: | | | | prescribed devices are:o Spectacle-mounted |
| Loss of Central Vision - the center of the person's | | | | magnifiers - A magnifying lens is mounted in the |
| view is blurred or blocked, but side (peripheral) vision | | | | individual's spectacles or on a special headband. This |
| remains intact. This makes it difficult to read or | | | | allows use of both hands to complete the close-up |
| recognize faces and most details in the distance. | | | | task, such as reading.o Spectacle-mounted telescopes |
| Mobility, however, is usually unaffected because side | | | | - These miniature telescopes are useful for seeing |
| vision remains intact. | | | | longer distances, such as across the room to watch |
| Loss of Side Vision - typified by an inability to | | | | television, and can also be modified for near (reading) |
| distinguish anything to one side or both sides, or | | | | tasks.o Hand-held and stand magnifiers - Serve as |
| anything directly above and/or below eye level. Central | | | | supplementary aids. They are convenient for reading |
| vision remains, however, making it possible to see | | | | such things as price tags, labels, and instrument dials. |
| what is directly ahead. Typically, loss of side vision | | | | Both types can be equipped with lights.o Electro-optical |
| affects mobility and slows reading speed because the | | | | aids - Closed-circuit television (also called CCTVs) |
| person sees only a few words at a time. Sometimes | | | | enlarge reading material on a video screen. Some are |
| referred to as "tunnel vision." | | | | portable, while some can be connected to a computer. |
| Blurred Vision - objects both near and far appear out | | | | The user can adjust the image brightness, size, |
| of focus, even with the best conventional spectacle | | | | contrast and background illumination. |
| correction possible and even when the target is very | | | | In addition, there are numerous other products to assist |
| large. | | | | those with low vision, such as large-type books, |
| Generalized Haze - the sensation of a film or glare | | | | magazines, and newspapers, books-on-tape, talking |
| that may extend over the entire viewing field and may | | | | wristwatches, self-threading needles, and more. |
| produce various patterns or areas of relatively severe | | | | If you, or someone you love, suffers from low vision, |
| vision loss. | | | | your optometric low vision specialist can provide the |
| Extreme Light Sensitivity - exists when standard levels | | | | help and resources needed to gain back the |
| of illumination overwhelm the visual system, producing | | | | independence and freedom that once seemed lost. |
| a washed out image and glare disability. People with | | | | People with low vision can be taught a variety of |
| extreme light sensitivity may actually suffer pain or | | | | techniques to perform daily activities with what vision |
| discomfort from relatively normal levels of illumination. | | | | remains. There are government and private programs |
| Night Blindness - inability to see outside at night under | | | | that offer educational and vocational counseling, |
| starlight or moonlight, or in dimly lighted interior areas | | | | occupational therapy, rehabilitation training, and more. |
| such as movie theaters or restaurants. | | | | Experts agree that low vision does not have to |
| Doctors of Optometry who specialize in low vision | | | | diminish the quality of life. As of October, 1999, both the |
| care are skilled in the examination, treatment and | | | | American Optometric Association and the American |
| management of patients with visual impairments not | | | | Academy of Ophthalmology have called for Medicare |
| fully treatable by medical, surgical or conventional | | | | coverage of low vision rehabilitation services. As |
| eyewear or contact lenses. Each type of low vision | | | | changes occur in Medicare policies and coverage, we |
| problem requires a different therapeutic approach. A | | | | will update this site to provide you with the latest |
| thorough examination by an optometrist, which will also | | | | information. |
| include tests to determine the patient's current vision | | | | Help is available today - don't wait to learn how low |
| status, may also include a vision rehabilitation program | | | | vision rehabilitation and your optometrist can make all |
| to enhance remaining vision skills. | | | | the difference! For referral to a doctor who specialized |
| The low vision specialist will ask for a complete | | | | in low vision, you can contact the American |
| personal and family general health and eye health | | | | Optometric Association at 314-991-4100. |