It is important to know how many lumens would be enough to read in bed, as this will prevent eye-strain and long-term vision loss, even if you read for long period.
In a nutshell, You only need 25 to 50 lumens (per square metre) on your book surface to read without eye-strain. More precisely, you need 25- 50 lux of illuminance. It means, those lumens of light should be focused on your reading area. Otherwise it might happen that you have a 500 lumens producing bulb in your room, but still not getting the required illuminance/brightness on your book.
If we talk about book lights for reading in bed, then most of these have with a very focused light. That is why, even though they produce less lumens, they still brighten up your book pretty well.
How Lumens Relate to the Brightness?
To fully answer that how many Lumens of light is required for reading in bed?, you need to understand the lumens and how they relate to the illuminance/brightness.
Lumens is total amount of light coming out of the bulb, not the measure of the brightness on your book.
Brightness or illuminance is the amount of lumens of light on a surface area of one square metre. It is measured in lux, and depends on how much focused that light is? and how near it is to your book?
For example, there can be a light bulb on your wall, producing a lot of lumens, while your reading area is still not bright enough. It is because it designed to produce a more dispersed light that illuminates a large area
On the contrary, you can have a tiny clip on book light that feels very bright, but only produces a few lumens only. It happens when light sources are designed to focus all the lumens to one direction, and lighten up that area efficiently. Examples of these kinds of light sources are torch lights, book lights, and reading lamps.
Water Through Pipe Analogy
To understand the concept of brightness and lumens even better, let us take the analogy of water flowing through a pipe.
The amount of water that is flowing through the pipe is the lumens. But, all that water is not useful, if it is not directed properly to the target. For example, if you want to wash your car, or water your plants, you would want the water to flow in the direction you want. But if you want to water the whole garden, you will need a dispersed shower to evenly spray the lawn.
Here is a detailed video explaining lumens, and at 2:36 in the video, you will find the demonstration of water through pipe analogy. It will make it easier to understand the concept.
How to Brighten up your Reading area perfectly?
If you want to estimate, How bright your reading area would be using a particular bulb?, then not only look for
- How many lumens the light source is producing?
- but also check, How much focused those lumens are?
- and how near that light bulb is to your book?
Compare lumens of similar lights, only
You cannot compare how bright your book will be, by comparing the lumens of a wall bulb to a book light.
You cannot estimate the brightness of the light by knowing the lumens only. You also have to see how this light source is focusing the light.
But if you have two similar type of light sources, then you can compare how bright they can be, by looking at their lumens. It is because, both of those will focus the light in a same way. For example, you can compare the wall bulb with the same type bulbs, the book light with the same type of book lights, and the bedside lamps with the bedside lamps.
Now, when you have understood that how many lumens do you need for reading at night? Let’s discuss other things that are also required when reading in bed
Reading lights that provide enough lumens on your book surface for easy reading
For reading in bed, first you need to look for the light that is focused, and then check how many lumens it is producing. Here are the lights that produce focused light that is good for reading in bed.
1- Book lights
If you want to read in bed without eye-strain then a clip on rechargeable book light should be your first option. It is because, these are portable mini lights that is easy to carry where ever you go. There are also some very lightweight book lights that does not weight your books down. Plus, these are a great solution if you want to read in bed without disturbing your partner.
2- Bedside lamps
If you have a side table near your bed, you mostly read at the same place, and you do not want something to be attached to your book or Kindle, then bedside table lamps are a good option for you. Booklights are cheap, so you can also get a book light along-with a bedside lamp, and use whichever works best for you.
3- Floor Lamps
Floor lamps are useful if you also need an ambient light in the room, in addition to the focused light on your reading area. These are not stationary, rather you can move floor lamps from your bed to your lounger or at your favorite reading nook. If you think that you need a floor lamp and bedside lamps, then get the bedside lamps that also convert to the floor lamps.
4- Wall or Headboard mounted reading lights
Headboard reading lights are a good option, If you read at the same place in your bed. You do not have to charge the light, remember where it is, or manage it any way. Once installed, you just turn the light on and start reading.
How many lumens of light is enough for reading at night or reading in bed?
You only need a few lumens focused properly on to the book or the Kindle, that you are reading, so that it is bright enough for you to read without stressing your eyes. Usually, 25 to 50 lumens/square metres are enough.
And that is what most LED clip-on book lights, or reading lamps produce. Most of the best book lights have the option to also adjust the brightness, by adjusting the lumens. There are buttons on the head or the base of the book light that you click to change the lumens, hence brightness.
Is 200 lumens per square feet or 18.5 square metre or 18.5 lux is bright enough for reading?
As I said, you only need around 25 – 50 lumens per square metre focus properly on to your book reading comfortably. So, if you have that in mind, 200 lumens per square feet will be dimmer. But still, it is not too dim to cause problem while reading.
But if this question comes when you are looking to buy a light bulb for a room. You divide the lumens of that bulb over the room area to get this number. If that is the case, then the answer is, you cannot guarantee that there will be 25 lumens per meter square will coming to your book. There might be shadows and reflections, which decrease or disperse the light coming onto your book. So in this case, 200 lumens per square feet are not enough. I hope you get the point.
Does Watts effects Lumens?
Yes, watts effects lumens, and hence brightness. More watts means more lumens. But there is more to it. You also need to take care of the how efficiently the bulb is utilizing the power.
Watts is the measure of how much electricity a certain bulb is using. LEDs are very efficient is utilizing electricity, so they produce more lumens per watt as compared to incandescent or CFL bulbs.
It is possible that a 100 watt incandescent bulb produces less lumens as compared to a 10 watt LED produces more Lumens.
So, when buying book light, or reading lamps for reading at night, you do not need to look at the watts. Just look how many lumens it is producing, and how the focused they will be on your book.
A more focused, less lumens, and less wattage book light is better than the less focused, more lumens, and more wattage book light. It is because, you get a brighter book to read by spending less electricity and without flooding the whole room with the light, which will also disturb others sleeping in the room.
Are incandescent or LED lights better for reading in bed?
It does not matter whether the light bulb is LED or incandescent, what matter is the brightness and the color of the light. Plus, it also does not matter how many lumens it is generating, what matters is, how a book light is focusing those lumens to light up. Your reading area must be well lit with a soft and even light.
What color light is good for reading in bed?
The color of the light also matters a lot when reading in bed before sleeping. If it is a cool color light, then it will disturb your sleep and also stresses eyes. But if, it is a warm yellow color light that is focused and properly diffused, such that there are no hot spots and glares, then it is the best light to read in bed. This will not disturb your sleep cycles, and will also be very easy to your eyes. Check in detail, which color is best for reading at night, White or yellow?