Lighting for Older Eyes

INTERVIEW WITH MARGARET P. CALKINS, PHD

Dr. Calkins: As people age, changes in vision occur that affect the ability to perceive and understand the world around them. For instance, there are normal age-related changes in the pupils (less light can enter the eye), the eyes’ accommodation speed decreases (it takes longer for eyes to transition to different light levels), and color perception weakens (yellowing of the lens makes it difficult to distinguish greens from blues). Older eyes also become more sensitive to glare-both direct glare (from a directly visible lighting source, such as an unshielded bulb) and indirect glare (a consequence of bright light bouncing off reflective surfaces, such as shiny floors). Compounding the problem is that many older adults develop diseases such as glaucoma, macular degeneration, and cataracts.

So much information about our surroundings comes directly from vision. I recently heard a surgeon relate a conversation he had with a patient. When he advised her to leave her eyeglasses at home, she said, “I need my glasses to hear you. I look at your face and your mouth when you speak, and then I can understand what you say to me.”

How can facility lighting compensate for visual deficiency?

Dr. Calkins: On the most basic level, the goal of lighting design for older adults is to increase foot-candles, which are units of illumination on a surface, without increasing glare. An excellent way to accomplish this when ceiling heights are sufficient (generally a minimum of 8’6″, preferably 9′, for indirect lighting) is through cove or indirect light that is bounced off the ceiling. This indirect lighting provides even, low-glare illumination. However, because the ceiling absorbs some of this light, it requires more foot-candles to achieve adequate lighting.

It is also important that bulbs meet the appropriate Color Rendering Index (CRI), so that colors appear natural (i.e., as they are seen in sunlight). For a long time fluorescents have been the only color-correct, energy-efficient alternative to expensive incandescent bulbs. Now color-correct metal halide bulbs are available. These bulbs provide cost-savings because of their long life and energy efficiency. They often take up to five minutes to “warm up” to achieve full light output. The benefit of this is that the eyes, especially older eyes, have an opportunity to gradually adjust to the light level.

What areas of a facility can most often be identified as in need of improved lighting?

Dr. Calkins: These areas vary from facility to facility. Common problem areas include hallways where ceiling lights are set too far apart, creating deceptive alternating light/dark patterns as a person walks down the hall. Poorly lit dining rooms can result in insufficient nutritional intake and a variety of other consequences, simply because residents cannot see their food. We recently conducted a research project in which the dining room provided only five foot-candles of light at the table, which is well below the 50 foot-candle recommendation. It’s no wonder that all the residents in this facility need assistance with eating.

Transitional areas also present lighting challenges for older people. On a bright day, a person entering the building from outdoors might have to stop and wait up to 90 seconds for his or her eyes to adjust to the lower light levels indoors. Bathrooms and treatment rooms also need to have appropriate lighting because in these areas people frequently change body positions and need to navigate safely.

Proper lighting doesn’t concern only residents, does it? What recommendations do you have to improve light levels for staff and other building visitors?

Dr. Calkins: Because of the close visual work that staff do, proper task lighting that removes glare can improve their concentration, make their tasks easier, and keep them from becoming overtired. Increasingly, care records are being computerized, so paying attention to light sources in relation to computer screens is important. Staff retreat rooms are generally an afterthought, but with nationwide staffing shortages, paying attention to such details as lighting in these areas can help show staff that they are valuable and that the organization cares about their needs.

The residents, meanwhile, are not the only older people in the facility. Often, their visitors are well on in years, and it is important to address lighting in parking areas, walkways, and lobbies. Chandeliers with clear glass, exposed bulbs should be avoided.

What new technologies have been applied to long-term care lighting?

Dr. Calkins: Metal halide bulbs are probably the hottest new technology in lighting for older adults. A number of remote and automatic-sensing systems are available, although not widely used. These include motion sensors that automatically turn lights on when someone enters a room. The problem is that they also automatically turn lights off if no movement is detected within a certain period of time. Consequently, they are best used in rooms or areas, such as bathrooms or utility rooms, where people don’t spend too much time.

Other technologic advances include voice-command light switches. These are available through many home technology catalogs, but are not widely used in long-term care facilities as yet.

One of the most common lighting problems that can be easily and affordably corrected is replacing those switch plates that are the same color or pattern as the walls. Often they are covered in the same wallpaper to provide continuity with the wall. These switch plates become virtually invisible to anyone with any vision loss. By color contrasting the switch plates with the walls, it makes them easier for older adults to locate. Also, pay attention to the location of switches. Obviously they should be positioned low enough for someone seated in a wheelchair to reach easily. Double-switching fixtures so they can be turned on from several locations in the room can also give an older person more control over the lighting in his or her environment.

As technology advances, I can envision the day when lights will not be hardwired to switches, thus allowing greater flexibility in locating switches to suit different users’ preferences.

What other improvements would you like to see in areas such as bulb technology, fixtures design, or lighting placement?

Dr. Calkins: I would like to see flexible lighting options within spaces or rooms. This relates primarily to what I said before about switching options (not putting all lights on a single switch, but have them on multiple switches). Providing different types of lighting within a space would also greatly benefit residents because they could adjust lighting to their immediate needs, such as overall ambient lighting to evenly light a space. By having task lighting in certain areas, wall sconces, and small track lights to highlight, for example, an interesting piece of art, room lighting becomes more dynamic, interesting, and enjoyable. Using rheostats, or dimmers, is another useful strategy, because this allows the resident to adjust light levels to accommodate specific situations and personal preferences.

At present, only a few manufacturers are incorporating new, improved light-bulbs into their fixtures. I’d like to see more innovation in this area.

Finally, there needs to be a conscious effort on the part of manufacturers to develop low-cost fixtures, because the reality is, that’s what most facilities will end up using.

You mentioned addressing lighting issues in the design phase. Do you have any recommendations on retrofitting existing buildings?

Dr. Calkins: It’s difficult to do indirect lighting in existing facilities because of low floor-to-ceiling heights in most cases. Even if the existing construction has sufficient height, the space above the drop ceilings is often full of air vents, sprinkler lines, communication wires, and other systems that can be expensive to remove or reconfigure. Depending on the wall construction (CMU [concrete masonry unit, or concrete block], for instance), running new electrical lines to wall sconces can also be an expensive proposition.

However, many existing lamps can be retrofitted with the color-correct metal halide bulbs at very little cost. Even a simple improvement in lighting is an improvement in quality of life for residents.

If an organization wants to know if its lighting is appropriate for its residents, where can it get more information?

Dr. Calkins: A good source is the Illuminating Engineering Society of North America (IESNA). The IESNA standards for senior environments have recently been revised. Lighting and the Visual Environment for Senior Living, RP-28-98, is available on the society’s Web site, www.iesna.org. NH