How much light you need for reading and writing

Reading needs more than a bright lamp: good placement, background light and a comfortable colour matter too. Practical rules for working on books and notebooks without strain.

Half an hour into an evening book, your eyes get tired and the lines start to blur. A child doing homework bends right down over the notebook. The first idea in such cases is usually a more powerful lamp. But for reading light, where the light comes from, how it contrasts with the background and how it reflects off the page matter just as much as output.

How much light is enough

By comparison, EN 12464-1 sets 500 lux on the desk for writing and reading at work. There is no mandatory standard for homes, but this figure is a good reference for long periods of reading and writing. For short reading, such as a few pages before sleep, less light can be comfortable too.

In practice this level is hard to achieve with a ceiling lamp alone: it is far from the desk, and much of its light spreads around the room. So a reading spot almost always needs local light, whether a desk lamp, floor lamp or wall light.

The age factor

With age, the amount of light reaching the retina decreases: the pupil gets smaller and the lens becomes less transparent. That is why a reader of seventy needs far more light on the page than a reader of twenty. Keep this in mind when setting up a reading corner for a grandparent: a stronger local lamp and the ability to hold text close to the light matter a lot.

If there is a concern about eyesight, more light is no substitute for an eye examination; sometimes the real problem is glasses that need changing.

Lamp position: shadows and reflections

A powerful lamp in the wrong place gives worse results than a weaker one placed correctly.

Shadows. When writing, light should come from the side opposite the writing hand. Right-handers should have the lamp to their left; left-handers, to their right. Otherwise the hand and pen cast a shadow where you are writing.

Reflections. Glossy paper, magazine pages and tablet screens reflect the lamp back into your eyes. Place the lamp slightly to the side and above rather than straight in front of you, so light falls on the surface at an angle and the reflection goes away from your eyes.

Glare. A desk lamp's shade should keep the lamp itself hidden from the seated person. If a bare lamp is at eye level, the eyes tire quickly even when the text is well lit.

Do not forget background light

Reading in a dark room with only a desk lamp is a common habit, but not the most comfortable one for the eyes. There is a big contrast between the bright page and the dark surroundings. Each time you look up from the book, your eyes have to readapt, and that adds to fatigue.

The solution is simple: keep some low general light on in the room while reading. It could be the ceiling lamp, a wall light or a floor lamp in the corner. The aim is not to make the room bright, but to soften the difference between the desk and its surroundings.

Colour temperature and light quality

Neutral white light, around 4000K, suits many people for writing and study that demands concentration: text looks sharp with good contrast. For relaxed evening reading, warm light at 2700–3000K creates a more restful atmosphere and interferes less with winding down for sleep.

Besides colour temperature, check two more things:

• Colour rendering. With a lamp of Ra 80 or higher, text and images look natural; a higher Ra helps when working with coloured materials, maps or drawings.
• Flicker. Even flicker you cannot see can cause discomfort during long reading. Choose a lamp with a good-quality driver.

A checklist for your reading spot

• Is there enough light on the desk or at book level? If possible, check roughly with a lux meter or phone.
• Is the lamp on the side opposite the writing hand?
• Can the seated person see the lamp itself?
• Is there a bright reflection on the paper or screen?
• Is there some low background light in the room?
• Does the light colour suit the task and the time of day?

If you answer "no" to two or more of these, try moving the existing lamp before buying a new one.

Zaferoğlu Elektrik's E27 and E14 LED lamps are made in different outputs for desk lamps, wall lights and floor lamps; when choosing for a reading spot, pay attention to the size of the shade and the lamp's distance from the desk.