Light Therapy for Alzheimer’s & Dementia: How it Works

Last Updated: July 19, 2021


Simply sitting with a bright light for 30 minutes each morning can improve the days and nights for your loved one with dementia. Light therapy has been studied in a clinical setting, and researchers say it offers effective relief from some of the devastating symptoms of Alzheimer’s disease and related dementia, including insomnia at night, fatigue during the day, aggressiveness, depression, and wandering. There is even evidence that bright light therapy works as well as some medications to slow the progression of dementia.

Another type of therapy called red light therapy uses special bulbs to stimulate the brain and increase communication between cells. Red light therapy, studies are showing, also relieves some of the problems most often associated with dementia.

On this page, we’ll explain light therapy—what it is, how it works, why it works, and how you can get and use simple lighting devices at home to help your loved one with dementia.


Benefits of Bright Light Therapy for People with Dementia

Symptoms related to sleeping and circadian rhythms can be serious problems for people with dementia. Insomnia at night is common, leading to wandering and an increased risk of falls. People with Alzheimer’s disease will sometimes be awake as much as half the night when they should be sleeping, and this causes tiredness during the day, leading to more trouble with thinking and memory and, in the evenings, sundowning. (Sundowning is increased aggression or aggravation in the evening.)

The part of the brain that controls circadian rhythms, the biological clock that makes us feel awake in the daytime and sleepy at night, is located in the hypothalamus, which connects directly to the eyes. Projecting light in specific ways at the eyes causes an effect in the hypothalamus that is something like resetting or realigning the circadian rhythm.

People with Alzheimer’s (and related diseases including vascular, frontotemporal, and Lewy body dementias) lose their natural circadian rhythms. Trouble sleeping, in fact, is one of the leading causes of institutionalization for two primary reasons:

1. caregivers become fatigued and frustrated
2. wandering at night is dangerous

By some estimates, people with dementia spend an average of 40% of the night awake. The consequences of this include increased rates of falling as well as increased agitation during the day and, especially, in the evenings.

Bright light therapy, according to studies, helps reestablish a circadian rhythm to:
– Improve nighttime sleep
– Increase daytime wakefulness
– Reduce aggression and agitation during the day
– Reduce sundowning
– Reduce falls

 Light Therapy With Melatonin. Giving melatonin supplement pills to your loved one can also help dementia symptoms. Combining light therapy sessions in the morning with 5 milligrams of melatonin at night has been shown in studies to improve wakefulness during the day and sleep at night.


How to Administer Bright Light Therapy

Bright light therapy is a simple process requiring only the purchase of an affordable light box. These are the steps you need to take to start getting relief from bright light therapy for your loved one with Alzheimer’s disease or related dementia:

1. Talk to the Doctor
There are very few side effects to bright light therapy, but it’s still important to talk to your loved one’s doctor before beginning for these reasons:
– If there is a family history of macular degeneration, the box could negatively affect your loved one’s eyesight.
– Certain medications can cause photosensitivity, meaning the skin is irritated by exposure to bright light.
– Issues like headaches might occur. The headaches usually pass after a few days, but you still want to keep your loved one’s doctor in the loop.

2. Get the Light
The unit for measuring a light’s intensity is called a lux, and you want a light box that produces 10,000 lux. (Sunlight on a clear day is about 50,000 lux.) Light boxes, also called light therapy lamps, usually run between $20 and $200. Look for lamps that are UV-free because you don’t want your loved one exposed to ultraviolet light. Some lights also come with a timer.

3. 30 Minutes Per Day
Have your loved one sit comfortably, with the lamp between one and two feet away. It’s OK to read, work on the computer, flip through pictures, or do anything else that keeps them in their seat while the light shines. Adjust the light so it is not aimed directly at their eyes. Set a timer for 30 minutes, though up to an hour is OK. The best time of day for light therapy is morning, between 8 and 11 a.m.

4. Be Consistent
Don’t skip sessions. It usually takes about two weeks for someone to start feeling the benefits of light therapy, though sleep may start improving within a few days. The key is consistency from day to day.


Benefits of Red Light Therapy and Photobiomodulation

Another form of light therapy is called brain photobiomodulation, in which near-infrared lights are placed around the head to emit a pulsing light set to a particular intensity (40 Hz) intended to stimulate the brain and improve communication between cells. Photobiomodulation delivers “light energy” to the brain that is absorbed by cells and turned into energy. Studies suggest that photobiomodulation (also called low-level laser therapy) benefits people with mild to moderately severe Alzheimer’s or related dementia by increasing blood flow and metabolism in the brain.

There is even a company called Vielight who makes devices that deliver photobiomodulation or near-infrared light therapy at several points around the head including inside a person’s nose. Because there are no barriers through the nasal passages, Vielight says, its therapeutic lighting is delivered directly to crucial parts of the brain for gentle stimulation that works to heal areas broken down by illness.

There is evidence that near-infrared light therapy can help with healing a traumatic brain injury (TBI). Though TBI differs from Alzheimer’s and other dementias in that it is caused by a blow to the head, the symptoms can be similar (including memory loss and changes in personality), and beneficial therapies including red or near-infrared light therapy might help heal brain cells for loved ones suffering from these diseases.


Bright Light Therapy in Assisted Living / Memory Care

Because light therapy has been shown to help sleep patterns and dementia symptoms, many assisted living homes for residents with dementia (also called memory care) have installed special lighting in certain areas, or implemented programs to get residents in front of these lights to start feeling the therapeutic benefits. If you are considering moving your loved one into memory care, it’s a good idea to ask about light therapy. If it isn’t available, then you can always take matters into your own hands and buy a light box for your loved one yourself.

If your loved one currently resides in memory care, talk with administrators about whether a light therapy program could be started. Or, again, you can purchase a light box for your loved one yourself. If you have to purchase it yourself, get the staff’s help to be sure it’s administered for the right amount of time each day (see above).


Status of Clinical Trials for Light Therapy

While the studies cited above offer evidence that light therapy, especially at 10,000 lux or 40 Hz, can help relieve the symptoms of Alzheimer’s disease and related dementia, the numbers of study participants are relatively small compared to clinical trials that are currently underway and expected to be completed in 2023.

Specifically, researchers are testing an iPad app called “AlzLife” on 2,000 participants to see if exposure to 40 light flashes per second for at least 30 minutes daily can improve thinking ability in people with Alzheimer’s. Researchers have already seen the flashing lights reduce the amount of beta-amyloid in the brain of laboratory mice with Alzheimer’s. (Amyloid-beta is a protein found in the brains of people with Alzheimer’s disease; most medications for Alzheimer’s are meant to reduce amyloid-beta.)

Unfortunately, these light therapy clinical trials are closed to new participants, but results are expected in 2023, and an easily accessible tool for administering light therapy might be released after that, depending on the data. For more information, click here.


Light Therapy Costs and Insurance Coverage

Insurance companies differ on whether they will cover the costs of purchasing devices for light therapy. Many published studies (see links throughout this page) have demonstrated light therapy’s effectiveness for helping with symptoms of Alzheimer’s disease and related dementia, especially when it comes to problems with sleeping and wakefulness. For this reason, it’s a good idea to contact your insurance provider and ask whether a light box or other device for administering light therapy might be covered.

Unfortunately, the Food and Drug Administration (FDA) has not officially ruled on whether it considers light therapy viable. For this reason, Medicare probably does not cover the costs of light therapy for people with dementia. However, Medicare Advantage combines with private companies to expand coverage for medical services and devices, and so it’s possible that specific Advantage plans might help pay for a light box or photobiomodulation headset.