Dear Jim: I am planning to get a high-intensity SAD (seasonal affective disorder) light or sunrise device to help reduce my wintertime blues. Do these things really work, what features should I look for, and are they expensive to use? – Kimberly J.

Dear Kimberly: SAD blues supposedly are caused by the reduced number of daylight hours during winter. I am not a physician, but some people claim the proper use of lighting devices can help reduce problems with SAD. Before trying to treat yourself for SAD, always consult your doctor first to discuss your specific problems.

Some hospitals have SAD light-therapy rooms, which you can use for a fee. If your local hospital offers this, it is a good way to determine if the light therapy helps you. A SAD light-therapy box with a stand costs several hundred dollars to purchase.

Almost all of the SAD light boxes use several long fluorescent tubes for the light source. Fluorescent tubes use about 25 percent as much electricity as standard incandescent light bulbs, and they last many times longer. Since the light box is used for only a short period each day, the electricity usage and overall cost are not great.

It used to be thought that using full-spectrum bulbs, which simulate the natural white light from the sun, was important. Today, many experts believe the intensity of the light on one’s eyes is more important than the natural appearance of the light.

Most SAD light boxes produce a minimum of 10,000 lux of light intensity. This sounds bright, but consider the light intensity outdoors on a clear, sunny day is as high as 90,000 lux.

At 10,000 lux, you can easily read the newspaper or magazines without uncomfortable glare. The typical SAD light box is lightweight, about 2 feet long and 4 inches deep.

The intensity of the light is also a function of how far your eyes are from the light box. When you compare SAD light boxes from various manufacturers, ask at what distance they produce 10,000 lux light intensity.

If the distance is too small, you will have to have the light uncomfortably close. A distance of about 18 to 24 inches generally is reasonable.

In addition to SAD light therapy boxes, other devices are used to combat wintertime SAD. You mentioned a sunrise device.

These are actually called dawn simulators. Many have an alarm clock built into a lamp. Other models have an outlet into which you plug a lamp.

About 30 minutes before the alarm goes off, the dawn simulator slowly begins to brighten the bulb to simulate the sun’s coming up.

Even though you are sleeping, the light will penetrate your eyelids, similar to real sunlight. Another device is the lighted, simulated windows with changeable scenes.