The Dos and Don'ts of Light Therapy for SAD with Macular Degeneration
S.A.D. stands for seasonal affective disorder which is a type of depression that some people are prone to in the fall and winter months when the hours of the day that are light are reduced. Its timing and severity can depend on where you live. The farther away from the equator, the higher the risk for SAD (I've dropped the "."). The symptoms are the same as depression: lack of energy, weight gain from overeating, feeling hopeless, inability to concentrate, and not finding enjoyment in things that you enjoyed.1
Light therapy for seasonal affective disorder
Check out Andrea's article 'How to Beat Seasonal Depression With Vision Loss' for more information and for practical ideas as to how to deal with it. I am sharing what I've found about light therapy and what to look for if you want use a light therapy lamp (sometimes called lightboxes).
What is it?
One type of treatment for SAD is called light therapy. You sit in front of a lamp that has a light or lights that simulate daylight. It’s called 'bright light therapy' or 'phototherapy.' It’s also used to treat problems such as dementia, jet lag, general depression, and sleep disorders.2
The artificial light stimulates the brain's receptors that control our cycle of sleep and wakefulness. Those receptors also control our mood. For it to work, the light needs to go into the eyes not through the skin.
UV rays and blue light
If you have macular degeneration, you have been warned about the UV light from the sun. You’re told to wear sunglasses that filter out 100% of the UVA/UVB rays. What does that mean in terms of these lamps? It means you have to be sure to use a light that is going to filter out those harmful rays.
Before starting light therapy, talk to your medical doctor and your eye specialist. This type of therapy can interact with some medications (antibiotics, antidepressants, antipsychotics) and supplements (melatonin, St. John's Wort).3 You should not use it after cataract surgery because the eyes are still sensitive to light.
Understanding UV rays
Our eyes filter light. The front of the eye filters out the harmful UVA and UVB rays. Failure to protect it can cause cataracts. The back of the eye - the retina and especially the macula - filters out the harmful blue light. Failure to protect it contributes to the development and progression of AMD.
Blue light and seasonal depression
The light used for light therapy is considered white light which is what is visible in daylight. Blue light is not part of the visible spectrum and not included in white light. You can find more details in my article 'Does Looking at Electronic Devices Damage My Eyes?'
Be careful when looking for SAD lamps because there are some that emit only blue light which is NOT used for SAD.
Choosing a lamp
You may have heard of 'daylight' or 'natural light' bulbs and lamps. That means they emit the same harmful rays that the sun does. That means you need to look for a lamp that:4
- Emits no UV light or the lowest amount of UV light possible. The information with it should clearly state that it removes or filters UV rays.3 If it doesn’t do that, look for a cover that screens out these rays.
- Produces 10,000 lux of light. Lux is a measure of a light's intensity. Any less may not be effective. More may be damaging.
How to use light therapy lamps
This is just a quick overview. The details can be found in the references.5
- Place the lamp about 16 to 24 inches from your face.
- To be effective, your eyes need to be open, but DO NOT STARE DIRECTLY AT THE LIGHT!
- It's recommended to be used in the morning in the first hour after you wake up.
- Start using it slowly and work up to 20 or 30 minutes a day. More than that is NOT recommended.
There can be side effects for some people. If you have them, reduce the time you are using it to see if they resolve.3
- Irritability or agitation, especially for those with bipolar disorder
- Sleeping problems
- Eye fatigue
- Feeling tired
Using light therapy can help some people who experience seasonal affective disorder (SAD). It is important, however, to check with your medical doctor before starting it especially if you have certain diseases (eg. bipolar disorder, depression), take certain medications and supplements. Choosing a lamp where the light contains no UV light is critical to its safe use. Make sure you know how to properly use it before you start. If you have any side effects, reduce the time you use it.
Have you are are you using a SAD lamp? Tell us about your experience.
Has an eye doctor ever left you feeling confused?