Avoid bright light in the evenings and sleep in full darkness at night

14 11 2017

The secretion of melatonin hormone (sleep hormone) is disturbed if the evenings in bright light.

I would recommend avoiding these

  • Powerful blue wavelengths such as blue leds, including white light, eg light therapy device for about two hours before bedtime. This two hour time is very personal.
  • Watching your computer screen, mobile phone or iPad for about two hours before bedtime.
  • Playing computer games for about two hours before bedtime
  • Watching TV for about two hours before bedtime.
  • Avoid RGB LEDs (red-green-blue) in the evening or remove blue light of it.
  • Children should not have lighted night toys in bed. An astonishingly small amount of light (1.3 lumen) is enough to interfere with the secretion of melatonin hormone.
  • If you see the street lighting from the windows, get black, light-impermeable blinds.

If you usually are reading late in the evenings, consider whether it is necessary.

Try to sleep 9 or at least 8 hours in the night. If the room is not dark, use black eye shields which are available for example for long flights.

In your phone is may be available the color temperature control: Settings – Display – Comfort for eyes: turn on this, start at 19.00 or 2 hours before going to bed, ending at 7.00 the next morning or when you usually wake up.

Color temperature, as warm as possible (adjusting is generally not possible when the comfort of the eyes is in use).

Install f.lux (free) on your phone and laptop, justgetflux.com  Adjust its settings to fit. See also sleeping instructions on f.lux Facebook.

There may be too much blue in the f.lux light so that the most sensitive cannot sleep. In this case try blue light blocking glasses. Google Uxex Skyper amazon. Use them also, when you are working in the evening with computer or when you are looking at TV. These glasses remove 98 % of the blue light.

Use these glasses two hours before going to bed. You may fall asleep faster. They are excellent even before the night flight if you want to sleep on an airplane.

The small blue or green signal lights of electronic equipments in bedroom may cause problems of falling asleep.  If necessary, you can tape the LED lights with air-conditioning tapes or even better, completely remove the equipment from the bedroom.

Illumine the night-time route to the toilet or refrigerator with dim, light-emitting red-colored led candles or lights so you can find it right way. Do not light the normal lights at night. The toilet light at night should not be white, it will reduce the secretion of melatonin and may wake you up. Light in the toilet should also be dimmed red. You do not have to see your face at night. If there is light in the toilet from the windows, stop it with black blinds.

If you wake up at night, do not light the reading lamp to read. Even a 5-10 minute stay at night in the light will stop the melatonin hormone secretion and will awaken you.

In the morning

Powerful, blue or white light is excellent to awaken and end the secretion of melatonin. Light up the kitchen and WC with powerful, white light in the morning. Watch the morning TV in as bright a light as possible. Daylight-type light (5500 K) is the best. If the sun is shining, take a walk outside.

It is advisable to extend the light therapy time for the elderly in the morning because their eyes penetrate less light than the eyes of the young.

In sleep problems you can also turn to doctors who are familiar with sleep disorders and winter depression.

By following these advice, you will also stay healthier and you will avoid risk getting breast cancer, for example.

Ilkka Pekanheimo, lighting designer, Finland

ilkka.pekanheimo@gmail.com   fullspectrumlight.wordpress.com


Article 26.11.2017:

How to light the Finnish Flag, when Finland celebrates 100 years


Lighting at the Housing fair in Finland 2015

14 07 2015

The annual Housing Fair in Vantaa 2015 is the 46th event of its kind. 98% of Finland’s adult population knows the event. Lighting designer Ilkka Pekanheimo has evaluated the lighting of the houses at the Housing fair in Vantaa.  This leaflet tells more about the idea of housing fairs.

It’s amazing to think that even though we spend two-thirds of our time living under artificial lighting, we’re not paying attention to the consequences of this light for our body and mind. Whereas people are concerned about organic food, pure water and clean air, the element by which our very life came into existence – light – is often forgotten.

At the House Fair 2015, there were houses, where all lighting was done by using led lamps. This leads to a new problem in lighting:  led strips are reflecting from the shiny surfaces. Hence, one should choose the type of surface before lighting with led strips. Do not choose black shiny surface to the kitchen if you use led strips. If you choose shiny surfaces, choose indirect lighting.

One problem at the fair were blending lights, unfortunately found in almost all the houses. The colors of the interior were made incorrect by lighting in almost all the houses.

There is no 100 % correct opinion on the lighting. I hope that this evaluation would create discussion and would contribute to make the lighting quality better in homes in Finland and in the whole world.

In my Finnish blog you can see 400 lighting pictures. If you would like to see 6000 home lighting pictures more from Housing fairs 1998 – 2014, contact Ilkka Pekanheimo.

Best lightings

  • House 22, LakkaLaine.  Excellent indirect solutions, only a few glaring luminaires. The color rendering index of the lamps was not good.  The color temperature is too low.
  • House  26, Villa Kapee.Excellent indirect solutions, only a few glaring luminaires. The color rendering index of the lamps was not good.   The color temperature is too low.
  • House 29, Villa Chili.    Excellent indirect solutions. The color rendering index of the lamps was excellent.  The light was pure white, the color temperature was 5000 – 5500 K. Beautiful colors, no glaring. In utility room you can see comparison of light: red chili in the right box is lighted with 5500 K light and in the left box with 2900 K light.  You can see also the difference in the color of the flower. The difference is amazing.

In fact, Villa Chili is the only house at housing fair, which is lighted with 5500 K daylight. If I would evaluate only the light quality, lacking of glaring, and the correct colors of interior design, Villa Chili would be the winner.

Some good and bad examples from the fair


A daylight led strip (5500 K) is installed into aluminium bar, painted with white. The bar is in the position of 45 degrees and light is directed to the wall. The wall is painted yellow like yellow chili. This color makes a warm atmosphere to the room. The daylight led shows the color of the wall as original.


There is a led strip (5500 K) at the front rand of the kitchen cabin. It is directed to the back wall with help of the aluminium bar in the angle of 45 degrees. You can see very well on the desk, no glare, no reflecting light. The wall is painted yellow.


All working surfaces should be lighted. You should put indirect lighting also on the cabin. The light color of the kitchen hood should also be the same color. Children and short people should not see the light under the cabin.


Better alternative would be indirect lighting. These small led luminaires cause a restless atmosphere and too little light in the room. I prefer 5500 K led panels and bigger size.


A daylight led lamp in outdoor luminaire should show the colors of the nature as original. In this luminaire the lamp is too yellow. Also in the winter the snow would be white in daylight lighting. If you have dogs in the house, it does not matter. A better alternative for bollard luminaire is indirect lighting: put the led strip on the upper rand of the white wall and put a small moulding on it so that you will not see the strip, only the reflecting light.


Avoid these upwards directed luminaires. They cause a very bad glare, when you walk near the luminaire or when the children crawl on the floor. They have no lighting meaning, maybe they light only the birds, which are flying over. This is a useless luminaire.


When you paint the ceiling with strong red color in the children’s room, it may be a color psychological mistake only if it is strong red. Avoid also small led lamps, they are too bright when you see them from the bed.


A good way to light a bathroom. The 3 mm opal plastic should be ca. 72 % transparent and you can light it with led strip or led tube.


Switch off the light!


Try 5500 K 8 – 12 W daylight lamp in these luminaires. The luminaire turns pure white and the colors in the room correct. You can also see better in the room.


A led strip is reflecting from the dark working desk. Avoid this by using 45 degree aluminium bar for led.


This is bad light.


This is good lighting. In the evenings you need candles on the table.


Indirect light is a beautiful way to light. The light should be continuous no dark intervals should be. I prefer pure white, 5500 K daylight. This is too yellow. You do not need the small lamps on the ceiling. They make a restless atmosphere.


Lighting by RGB is according to my opinion an unnecessary trick. There are no studies to show, how the continuously changing color affects to peoples well-beeing. The effect is not undoubtedly positive. The eyes will strain, when they always must adapt to a new color world. Also the color of interior decoration changes all the time.


An excellent non-glare way to light a jacuzzi. How ever, this light may be the “white” from RGB. The color rendering index of RGB white is only 20, so never use it. A continuous changing RGB here is awful, but it is my opinion. Do not care about it.


An indirect lighting near to timbers is an excellent way to light. Even better, if you use 5500 K pure white light. The color of the wood would be original.


I would put colorful paintings on the wall and not these luminaires, which are changing the color of the wall. Lighting by indirect way.


The spot lights in the light bar is an easy solution but not elegant. The lamps are very glare when you look at them. The colors of the interior decoration will be destroyed because of the bad quality of the light. Too yellow, may be 2900 K. It should be 5500 K, in my opinion.


The correct installing place of the led strip is in front of the cabin and it should be directed to the back wall. You should not see the light at the long distance of the kitchen to the room. It has no use.


This is one of the worst way to light. The light causes glare and when it has a 2700 K lamp, the light destroys the colors of the room. If possible, turn the lamps towards the ceiling.

The lighting evaluation of the housing fair in Finland 2014

22 07 2014

In my Finnish blog you can see over 300 lighting pictures. If you like to see 6000 more home lighting pictures from Housing fairs 1998 – 2013, contact ilkka.pekanheimo@gmail.com

adlux.wordpress.com, here are only a few examples:

Wooden panel with led strips. Use full spectrum leds, 5500 K, it shows also the wood color original, not yellow like here.

Wooden panel with led strips. Use full spectrum leds, 5500 K, it shows also the wood color original, not yellow like here.

Avoid these lamps,  too bright,   awful lighting method.

Avoid these lamps, too bright, awful lighting method. Indirect lighting is much better.

Excellent lighting of stairs, led strip.

Excellent lighting of stairs, led strip.

Good indirect lighting, but with daylight led strips you could get it even better.

Good indirect lighting, but with daylight led strips you could get it even better.

Correct place of led strip under the cabin. in the front side of the cabin, the light should go to the direction of back wall.

Correct place of led strip under the cabin. in the front side of the cabin, the light should go to the direction of back wall.

Most of them are bad examples:

  • too bright lamps,  spotlight, dazzling lamps
  • warm tone lamps (2700 – 4200 K), which destroys the colors
  • destroys totally he work of interior decoration designer
  • lamps, which have no full spectrum

However, there are also good examples, e.g. indirect lighting. The whiter light – the better, if the type of the light is full spectrum. I recommend 5500 K. 6000 K is too blue.

Ask my comments from some pictures.  ilkka.pekanheimo@gmail.com

Children’s day-care center got health-promoting lighting

9 03 2014
In April 2014 in Turku was opened children’s day care center. It is lighted with full spectrum Viva-Lite daylight lamps.
  • 74 pcs 580 mm Jasmina plafonds, 2×36 W lamps
  • 8 pcs 800 mm Jasmina plafonds, 2×55 W lamps
  • 23 pcs plafond with presence detector, 2×18 W lamps
Full spectrum daylight lighting has many benefits. The colors and seeing accuracy are excellent, the reading speed is faster than in normal lighting. The light that has effects on health, it is especially important for children.
The children grown under daylight are less myopic and have less eye glasses
This has been showed by Australian and Swedish studies. The best light is, of course, full spectrum daylight outdoors. Also artificial full-spectrum daylight is useful if there is not enough real daylight. e.g. in winter time. Therefore, we recommend that the homes and schools would be illuminated with a stronger  daylight-like light and ask children to stay more in a real outdoor daylight. The longer a child stays outdoors in daylight, the better the vision he gets.  This is evident from the studies by Dr. Kathryn University of Sydney .
Children growing in daylight lighting has even less myopia, that means, the eye glasses are not often  needed .
Stockholm University study shows how important it is to study under full spectrum lamps. Full spectrum  lamps can help tired children. The survey found that schoolchildren were sharper. They were also more active during the day. In the evening, before going to bed, they were more tired. Movement monitors also revealed a better and more peaceful night’s rest.
Here are pictures of daylight Jasmina luminaires.  The lighting has got a lot of positive comments. It differs so much from the traditional.
Jasmina luminaires meets the needs of even the most difficult aspect of ergonomics and gives a pleasant smooth and efficient lighting. Because of the opal cover the brightness is low, and does not dazzle.
In 2015 a similar children’s day-care center will be lighted with full spectrum LED lamps.
More information 
Daylight effect on eye development. Dr. Kathryn research from the University of Sydney
Stockholm School Survey, University of Stockholm stress the Institute’s research

Habitare / Light fair in Helsinki in September 2013

6 10 2013

WT4-valolistan päällä on päivänvaloledinauha. Valo on puhtaan valkoista.

Habitare/Light fair (5 days) was excellent and very successful for me. There were over 54 000 visitors and this is much, because there is only 6,5 million people on Finland.
I had a 30 min. lecture every day.  This lecture was hold three times:  “Led lighting is coming – are you ready”. This was hold twice:  Daylight lighting as an element of  interior decoration.

After the lecture many people came and handshaked me, they told that the lecture was so excellent. The lighting and led information was so new for them.

I was also interviewed in Radio Nova, which is very popular in Finland, during the fair.  No other company at the light fair got such a publicity.


The lighting evaluation of the Housing fairs in Finland

1 08 2013

I have evaluated the lighting in the Housing fairs in Finland since 1999, so already 15th time in 2013.Valoa voisi olla hieman enemmänkin. (7)

The main theme of the Raisio housing fair 1997 was natural lighting and light quality.
In front of daylight house president Martti Ahtisaari told to the represents of the Press: “In my home there is also daylight lighting and I like it very much.”
There are total 6047 pictures in my page of the lighting solutions in the Finnish houses. Good and not so good solutions. There is comments in every picture and a school degree evaluation (10 the best, 4 worsest).

One of the best lighted houses in Finland

9 06 2013

It’s amazing to think that even though we spend two-thirds of our time living under artificial lighting, we’re not paying attention to the consequences for our body and mind. Whereas people are concerned about organic food, pure water and clean air, the element by which our very life came into existence – light – is often forgotten.

Päivänvalovalaistusta voidaan himmentää.
One of the best lighted houses in Finland, (June 2013) no halogens or GU-10 LED or similar lamps. A lot of light in a room, no blending, you do not need any ceiling luminaires. The customer is very satisfied. You can do the same with led lamps (strips and panels) but not with spot lamps.
Also this house is lighted near totally with indirect daylight, the customer is very satisfied.

A house lighted with full spectrum daylight at housing fair in  2009. Today I light more and more by daylight led lamps of highest quality. Look the video.