What is Low Vision?
Some individuals, even with glasses and contact lenses, cannot see well enough to do everyday activities. Most people develop low vision because of eye diseases and health conditions like macular degeneration, cataract, glaucoma, and diabetes. A few people develop vision loss after eye injuries or from birth defects. While vision that’s lost usually cannot be restored, many people can make the most of the vision they have. These people benefit from individualized specialty vision instruments. Some need help with magnifying near tasks, others with distance vision tasks and or peripheral vision. We can also prescribe glare/colored filters and electronically operated devices to improve visual input and mobility.
Common Types of Low Vision
- Loss of Central Vision – The loss of central vision creates a blur or blindspot,but side (peripheral) vision remains intact. This makes it difficult to read, recognize faces, and distinguish most details in the distance. Mobility, however, is usually unaffected because side vision remains intact.
- Loss of Peripheral (Side) Vision – Loss of peripheral vision usually limits the ability todistinguish anything to one side or both sides, or anything directly above and/or below eye level. Central vision remains, however, making it possible to seedirectly ahead. Typically, loss ofperipheral vision may affect mobility and if severe, canslow reading speed as a result of seeing only a few words at a time. This is sometimes referred to as “tunnel vision.”
- Blurred Vision – Blurred vision causes both near and farto appear to be out of focus, even with the best eye glasses possible.
- Generalized Haze – Generalized haze causes the sensation of a film or glare that may extend over the entire viewing field.
- Extreme Light Sensitivity – Extreme light sensitivity exists when standard levels of light overwhelm the visual system, producing a washed out image and/or glare disability. People with extreme light sensitivity may actually suffer pain or discomfort from relatively normal levels of illumination.
- Night Blindness – Night blindness results in inability to see outside at night under starlight or moonlight, or in dimly lighted interior areas such as movie theaters or restaurants.
Low Vision Devices
A wide variety of rehabilitation options are available to help people with low vision live and/or work more effectively, efficiently, and safely.
- Spectacle-mounted magnifiers / microscope – A magnifying lens is mounted in eye glasses or on a special headband. This allows use of both hands to perform close-up tasks, such as reading.
- Hand-held or spectacle-mounted telescopes – These miniature telescopes are useful for seeing longer distances, such as across the room to watch television, and can also be modified for near (reading) tasks.
- Hand-held and stand magnifiers – These are convenient for short-term reading of things suchas price tags, labels, and instrument dials. Both types can be equipped with lights.
- Video magnification – Table-top (closed-circuit television) or head-mounted systemsenlarge reading material on a video display. Some systems can be used for distance views tasks. These areportable systems, and canbe used with a computer or monitor. Image brightness,image size, contrast, and foreground/background color and illumination can be customized.
In addition, there are numerous other products to assist those with a vision impairment, such as large-type books, magazines, and newspapers, books-on-tape, talking wristwatches, self-threading needles, and more.