Light is essential to vision. The quality and quantity of the light needed for a comfortable, useful viewing environment varies from person to person and becomes particularly important when vision is impaired.
On average, older people need about three times as much light as those who are younger. Three times the light may be a good starting point for adjusting the amount of light, but ultimately an individual must be comfortable and must be able to accomplish visual tasks under those conditions. It's important to evaluate visual performance and comfort under varying lighting conditions to decide what works best for you.
For instance, people with glaucoma must balance their need for higher light levels with avoiding glare, while those with cataractsmay do better with lower light.
When the days get shorter, the need to make the most of light, whether natural or artificial, becomes more pronounced, especially for people with vision problems.
"The amount and quality of available light can make a tremendous difference in how well we see and manage daily activities, indoors and outside," notes Betty Bird, Ed.D., former Senior Vice President for Rehabilitation Programs at Lighthouse International. "Sometimes simple changes can greatly enhance a person's ability to complete a task."
For example, when reading print or handwritten material, you may want to try placing a clear yellow acetate sheet over the material. This easy adaptation, available where office supplies are sold, helps to increase contrast.
Here are some other suggestions that individuals with vision problems - as well as their friends and families – are sure to find helpful:
- Glare results when light (natural or artificial) shines directly into your eyes or reflects off shiny or polished metal surfaces, such as tabletops and floors. Use a tablecloth to cut the glare from a formica table.
- Keep lights on during the day to equalize lighting from indoor and outdoor sources. When arranging a room to be used for reading or working, don't face the windows. Seat yourself so that windows are behind you or to your side. If that's not possible, use blinds or shades to control the light during daylight hours.
- Light from lamps or fixtures should be positioned directly onto the task (book, newspaper, playing cards, hobby/craft, etc.). Gooseneck, adjustable arm, and clip-on lamps offer good flexibility. In dimly-lit restaurants use a pocket flashlight.
- When reading or working outside, use a visor to shut out sky light glare.
- Incandescent lamps or "warm" fluorescents may cause less glare to a person with cataracts than "daylight" fluorescents. Incandescent lamps may be easier to adjust because they tend to be smaller, and can be moved easily and controlled with dimmers. However, they're less efficient and radiate more heat, which may be a problem if a lamp has to be positioned close to the user's face or body.
If a complete rearrangement of lighting isn't possible, try adding an incandescent or fluorescent table lamp. This may be particularly useful in older, fluorescent-ceiling-lighted rooms.
- When located within one foot of the reading material, a standard 60, 75, or 100 watt bulb or a 50 to 65 watt indoor reflector bulb may be adequate. However, 300 watts or more may be needed in a floor lamp to achieve comparable light. Chromalux bulbs (60 or 100 watts) work well for some individuals with macular degeneration. Halogen lamps, a type of incandescent lamp, used in the proper fixture, are safe and efficient, and can provide high-intensity light in a small space.
- A type of fluorescent bulb is available as a direct, screw-in replacement for some incandescent bulbs. These bulbs consume from one-sixth to one-tenth as much electricity, radiate very little heat, and, although more expensive, last about 10 times as long as the conventional incandescent bulbs. In addition, these modern tri-phosphor compact fluorescent bulbs provide light very close to the quality of incandescent. They provide excellent color rendition - food looks natural, colors look normal - and offer a "comfortable" atmosphere for most people.
- Under-counter lighting can increase visibility for kitchen, study or work areas.
- Whatever the lighting arrangement, as task lighting is increased, so should the surrounding room lighting. For example, avoid using a very bright lamp in a dark room.