What is Lux and How Much Do I Need for Light therapy?


I was having trouble sleeping and someone suggested light therapy so I thought I would do some research.  I needed to know what Lux was and how much I needed for effective light therapy to choose from all the options out there.

So What Is Lux And How Much Do I Need?  Lux is the measurement unit for illuminance and is equal to one lumen per square metre.  It is usually recommended equipment with 10,000 lux is the most effective light therapy.  While other equipment might be less, you would need more frequent and longer applications and they may not be as effective.

While 10,000 lux is recommended for effective light therapy, there is actually a lot to choosing the right light therapy equipment with the correct amount of lux and lumen for the right condition.  You need to know the right colour of light to use.  You also need to know the exact distance you need to be from the bulb as choosing incorrectly could result in not getting the outcomes you want.

Is Lux and Lumens the Same?

Lux and lumens are both units of measurement for luminous flux.  Lux is the measurement of the light intensity at any point, so the amount of light on a surface per unit area.   The difference is that Lux takes into account the area over which the luminous flux is spread.

So lux = 1 lumen per square meter.

To give you some idea of how bright lumens are, if you wanted to replace the brightness of a 100 watt bulb, look for a bulb that gives you around 1600 lumens.

While light therapy equipment usually displays its brightness as a measurement of lux, it is imperative to know what distance the user needs to be from the bulb.  Any chance in distance or bulb type changes the lux level so this is an important component to getting the desired results.

Type of LightMeasurement in Lux
Direct Sunlight100,000 – 130,000
Daylight Noon100,000
Full Moon1
Street Lighting10
Home Lighting30 – 300
Office Desk Lighting100 – 1,000
Surgery Lighting10,000
Overcast Day1,000
Typical Living Room100

How Much Lux Do I Need For Light Therapy?

There are many different types of light therapies for different conditions.  Bright light therapy or full spectrum light is the closest we can get to mimicking full sunlight. For bright light therapy, which is commonly used to prevent depression and Seasonal Affective Disorder, you would use your daylight lamp (10,000 lux in a pure white light) for 20 – 30 minutes a day during the fall and winter months.  To get the full 10,000 lux you would need to sit 11 – 15 inches from the light.

It is possible to get a similar result from a 2,500 lux lamp but you would have to sit in front of it for 2 hours a day which is not so convenient.

Light TherapyBenefitsEquipment
Full Spectrum
Light Therapy
Mimics Sunlight
Helps with SAD
Improves mood
Boosts mental awareness
Maintains serotonin
Maintains melatonin
10,000 lux light lamp
UV Light TherapyDestroys bacteria, fungus
Destroys viruses
Improves immune system
Used for eczema, psoriasis
UV light bulb lamp
Infrared Light
Therapy
Heals chronic wounds
Boosts cancer healing
Helps chronic joint pain
Infrared heat lamp
Blue Light TherapyTreats acne, skin disorders
Destroys bacteria P (acne)
Blue wavelength
light bulb
Hand held device
Red Light TherapySun damage on skin
Wrinkles, aging
Enhances mitochondria
Fades stretch marks
promotes elastin, collagen
Red light lightbox

How Do I know If I Would Benefit From Bright Light Therapy?

Bright Light Therapy or Full Spectrum Therapy was originally designed for the treatment of Seasonal Affective Disorder. If you find there is a pattern where you experience any (or a combination of) these symptoms during fall or winter months, then bright light therapy may be beneficial for you.

  • Feeling depressed
  • Feeling down
  • Loss of energy
  • Fatigue
  • Lethargy
  • Moodiness
  • Excessive sleeping
  • Difficulty getting up in the morning
  • Weight gain
  • Craving of carbohydrates
  • Loss of sex drive

Other disorders may require year round treatment to obtain benefits.  These might include:

  • Non-seasonal depression
  • A frequent traveller
  • Sleep disorder
  • PMS

Could I Get The Same Benefit Increasing The Lighting At Home?

Indoor light cannot deliver the light needed for therapy. Light boxes are not just ordinary lights; they are light which simulate the intensity of daylight.

The light box is a bank of white fluorescent lights on a metal reflector and shield with a plastic screen.

Because the recommended dosage is 10,000 lux for 20 – 30 mins a day, it would be very difficult to get the same dosage by increasing lighting at home.

Typical lighting in a home is between 30 – 300 lux.  Even if you doubled the top amount, you still would not be anywhere near what is needed for light therapy.  In fact, it is impossible for any light fixture in a home to be upgraded past 600 lux.

It is also not recommended that you try and construct your own lighting apparatus as there could be electrical challenges that are not safe, and the amount of lux needed would be difficult to achieve anyway.

If I Spend More Time Outside Would That Work?

You could try spending more time outside but you would have to be outside for extended periods which is difficult.  Often in fall and winter months, the days are overcast or cloudy.

Cloudy days only have 1,000 lux so you would need to spend 10 hours each day to reach the recommended 10,000 lux.  With a normal work schedule, that just woudn’t be possible.  That is why many people are opting for 10,000 lux light lamps.  They can get the benefits they need in only 20 – 30 minutes a day in the comfort of their own home.

Other Related Questions:

When Is the Use of a Bright Light Therapy System Not Recommended?

Light therapy can be used by anyone.  However it is recommended that if you suffer from anyone of the following that you see your physician first.

  • Glaucoma
  • Cataracts
  • Retinopathy
  • Retinal detachment
  • Lupus
  • Diabetes
  • Taking medications that have photosensitizing effects (such as lithium or melatonin)

Can the 10,000 Lux Lamps Be Used for Anything Else?

The quality of light emitted from the bright light therapy lamps is pleasant and can be used for other things as well as light therapy.  If it is placed at least arm’s length away which is further than the recommended 11-15 inches for light therapy, it can be used as a reading lamp, or for working, especially for find work such as embroidery, drawing etc. 

It is important that the lamp be turned away from the face to create an ambient light.  As they are light weight, portable and height adjustable, they are easy to move around in the home to be used in other ways.

Are Bright Light Therapy Lamps Expensive to Purchase and Maintain?

Bright light therapy lamps of 10,000 lux have a huge price range.  They can be bought for as low as $30 and go all the way up to $500.

There are a huge range of brands and styles, with some that sit on a desk and others with height adjustable stands.

Amazon stocks a wide range of both less expensive and more expensive brands and styles.  If you have Amazon Prime, you can take advantage of free shipping.

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