The Windows 10 Night light: What it does and how to use it

Whether it is because we look at them too much or because they radiate too much blue light, screens are known to cause eye problems. It is almost impossible to avoid screens in our daily lives. There are also many night owls like ourselves, regularly watching our computers’ screens during the night. The good news is that Windows 10 includes a special night mode called Night light. It is a display mode designed to reduce eye strain by decreasing the blue light emitted by the screen of your Windows 10 PC, tablet or laptop. Here is what the Night light does in Windows 10, how to use it, and how to configure the way it works:

What is the Night light in Windows 10? What does Night light do?

When you find yourself working on your computer or laptop at late hours, you put a lot of pressure on your eyes. When you’re looking at your screen during nighttime hours, your irises contract to cope with the discrepancy between the bright light in front of you and the dark environment around you. Then, after some time, tears might also start coming to your eyes, your head might start to hurt, and sleep seems to run away from you. If you are a “night owl,” you are probably familiar with all these symptoms.

In recent years, evidence has appeared that the exposure to blue light causes eye fatigue and a whole range of health issues. It is what keeps you from sleeping, and it is what hurts your eyes.

Fortunately, big names from the tech world have started to take notice of this problem, and Microsoft is one of them. The company’s solution is called Night light: a display mode that changes the colors displayed on your screen into warmer versions of themselves. In other words, Night light partially removes the blue light from your screen.

The Night light was introduced with Windows 10 Creators Update, in the spring of 2017. Previous Windows 10 versions that were released before 2017 do not have this feature, but newer versions do. If you do not know what version of Windows 10 have, read: How to check the Windows 10 version, OS build, edition, or type.

How to enable Night light in Windows 10

Start by opening the Settings app. A quick way to do it is to open the Start Menu and click or tap on the gear Settings icon. In the Settings app, go to the System category.

On the left column, go to the section called Display. Then, on the right of the Settings window, find the section called Color and turn the Night light switch On.

By default, the Night light mode is scheduled to activate between sunset and sunrise. You can see its status displayed next to its name, between brackets. In the screenshot below, you see that the Night light feature is enabled, but does not turn on until 7:29 PM – the local time when the sun is going to set.

If you want to change the time when the Night light is turned on in Windows 10, and the strength with which it filters the blue light, read the next sections in this guide.

How to adjust the color temperature of the Night light from Windows 10

To make changes to the way Night light works in Windows 10, click or tap on Night light settings, right under the Night light switch.

In the Night light settings, you get a short explanation about the fact that “Screens emit blue light, which can keep you up at night. Night light displays warmer colors to help you sleep”. Then, you get a button that can be used to manually turn the Night light on, right now, even if its schedule does not allow it to run at the time when you are enabling it. You also see a slider called Strength.

Dragging this slider to the right makes your screen use warmer, yellowish colors to reduce eye strain, while dragging it to the left, makes it use the regular cooler and bluish hues. Play with this slider and see what the color temperature that feels best to you at night is. You should fiddle with the slider at night, and not during the day. This makes it easier to find the right setting, because you can feel when your eyes begin to relax.

How to set the schedule for the Night light

In the same “Night light settings” window, below the Strength slider, you see a section called Schedule. If you turned the Night light On, the Schedule night light switch is also On and set to be applied between Sunset to sunrise. The exact time of sunset and sunrise is automatically calculated by Windows 10 depending on your location, and date.

If you want to schedule the Night light mode to be applied automatically during specific hours of the day, click or tap the “Set hours” option and manually select the Turn on and Turn off times.

That is everything that you can configure about the Night light mode in Windows 10.

The quick way of turning the Night light On and Off

There is a faster way of turning the Night light mode On or Off in Windows 10, besides going through the Settings app. Open the Action Center by clicking on its icon in the bottom right corner of your screen, or by pressing Windows + A on your keyboard. You can also slide your finger from the right edge of the screen if you have a device with touch. Then click or tap on Expand to see all the available quick actions.

In the quick actions section, click or tap on the Night light button to toggle it from On to Off and the other way around.

When you want to stop using the Night light, repeat the same steps.

Do you like the Night light in Windows 10?

Even if you work late long hours, that does not mean that you cannot take care of your health, including your eyes and sleep. Reducing blue light helps in this matter, so Microsoft decided to give us a night mode that does just that. Try the Night light and see how it works for you. Then, come back and tell us if it helped reduce the strain on your eyes and if you managed to sleep better.

Window

A window is a transparent or translucent opening in a wall or door that allows the passage of light and, if not closed or sealed, air and sound. Windows are usually glazed or covered in some other transparent or translucent material like float glass. Windows are held in place by frames, which prevent them from collapsing in. Many glazed windows may be opened, to allow ventilation, or closed, to exclude inclement weather.

Contents

Etymology

The word window originates from the Old Norse ‘vindauga’, from ‘vindr – wind’ and ‘auga – eye’, i.e. «wind eye«. In Norwegian Nynorsk and Icelandic the Old Norse form has survived to this day (in Icelandic only as a less used synonym to gluggi), in Swedish the word vindöga remains as a term for a hole through the roof of a hut, and in the Danish language ‘vindue’ and Norwegian Bokmål ‘vindu’, the direct link to ‘eye’ is lost, just like for ‘window’. The Danish (but not the Bokmål) word is pronounced fairly similarly to window.

Window is first recorded in the early 13th century, and originally referred to an unglazed hole in a roof. Window replaced the Old English ‘eagþyrl’, which literally means ‘eye-hole,’ and ‘eagduru’ ‘eye-door’. Many Germanic languages however adopted the Latin word ‘fenestra’ to describe a window with glass, such as standard Swedish ‘fönster’, or German ‘Fenster’. The use of window in English is probably due to the Scandinavian influence on the English language by means of loanwords during the Viking Age. In English the word fenester was used as a parallel until the mid-18th century and fenestration is still used to describe the arrangement of windows within a façade.

From Webster’s 1828 Dictionary: Window, n. [G. The vulgar pronunciation is windor, as if from the Welsh gwyntdor, wind-door.] [ 1 ]

History

Primitive windows were just holes in a wall. Later, windows were covered with animal hide, cloth, or wood. Shutters that could be opened and closed came next. Over time, windows were built that both protected the inhabitants from the elements and transmitted light: mullioned glass windows, which joined multiple small pieces of glass with leading, paper windows, flattened pieces of translucent animal horn, and plates of thinly sliced marble. The Romans were the first to use glass for windows. In Alexandria ca. 100 CE, cast glass windows, albeit with poor optical properties, began to appear. Mullioned glass windows were the windows of choice among European well-to-do, whereas paper windows were economical and widely used in ancient China, Korea and Japan. In England, glass became common in the windows of ordinary homes only in the early 17th century whereas windows made up of panes of flattened animal horn [ citation needed ] were used as early as the 14th century in Northern Britain. Modern-style floor-to-ceiling windows became possible only after the industrial glass making process was perfected.

Types of windows

Double-hung sash window

This sash window is the traditional style of window in the United Kingdom, and many other places that were formerly colonized by the UK, with two parts (sashes) that overlap slightly and slide up and down inside the frame. The two parts are not necessarily the same size. Nowadays, most new double-hung sash windows use spring balances to support the sashes, but traditionally, counterweights held in boxes on either side of the window were used. These were and are attached to the sashes using pulleys of either braided cord or, later, purpose-made chain. Double-hung sash windows were traditionally often fitted with shutters. Sash windows may be fitted with simplex hinges which allow the window to be locked into hinges on one side, while the rope on the other side is detached, allowing the window to be opened for escape or for cleaning.

Single-hung sash window

One sash is movable (usually the bottom one) and the other fixed. This is the earlier form of sliding sash window, and is also cheaper.

Horizontal sliding sash window

Has two or more sashes that overlap slightly but slide horizontally within the frame. In the UK, these are sometimes called Yorkshire sash windows, presumably because of their traditional use in that county.

Casement window

A window with a hinged sash that swings in or out like a door comprising either a side-hung, top-hung (also called «awning window»; see below), or occasionally bottom-hung sash or a combination of these types, sometimes with fixed panels on one or more sides of the sash. In the USA, these are usually opened using a crank, but in parts of Europe they tend to use projection friction stays and espagnolette locking. Formerly, plain hinges were used with a casement stay. Handing applies to casement windows to determine direction of swing; a casement window may be left-handed, right-handed, or double. The casement window is the dominant type now found in the UK and parts of Europe.

Awning window

An awning window is a casement window that is hung horizontally, hinged on top, so that it swings outward like an awning. Emilie Poisson designed this window.

Hopper window

A hopper window is a bottom hung casement window that opens similar to a draw bridge typically opening to the outside.

Tilt and slide window

A window (more usually a door-sized window) where the sash tilts inwards at the top and then slides horizontally behind the fixed pane.

Tilt and turn window

A window which can either tilt inwards at the top, or can open inwards hinged at the side. This is by far the most common type of window in Germany, its country of origin. It is also widespread in many other European countries. [ 2 ]

Transom window

A window above a door; in an exterior door the transom window is often fixed, in an interior door it can open either by hinges at top or bottom, or rotate on hinges. It provided ventilation before forced air heating and cooling. A fan-shaped transom is known as a fanlight, especially in the British Isles.

Jalousie window

Also known as a louvered window, the jalousie window consists of parallel slats of glass or acrylic that open and close like a Venetian blind, usually using a crank or a lever. They are used extensively in tropical architecture. A jalousie door is a door with a jalousie window.

Clerestory window

A window set in a roof structure or high in a wall, used for daylighting.

Skylight

A flat or slope window used for daylighting, built into a roof structure that is out of reach.

Roof window

A sloped window used for daylighting, built into a roof structure.

Roof lantern

A roof lantern is a multi-paned glass structure, resembling a small building, built on a roof for day or moon light. Sometimes includes an additional clerestory. May also be called a cupola.

Bay window

A multi-panel window, with at least three panels set at different angles to create a protrusion from the wall line.

Oriel window

A window with many panels. It is most often seen in Tudor-style houses and monasteries. An oriel window projects from the wall and does not extend to the ground. Oriel windows originated as a form of porch. They are often supported by brackets or corbels. Buildings in the Gothic Revival style often have oriel windows.

Thermal window

Thermal, or Diocletian, windows are large semicircular windows (or niches) which are usually divided into three lights (window compartments) by two vertical mullions. The central compartment is often wider than the two side lights on either side of it.

Fixed window

A window that cannot be opened, whose function is limited to allowing light to enter (Unlike an unfixed window, which can open and close). Clerestory windows are often fixed. Transom windows may be fixed or operable. This type of window is used in situations where light or vision alone is needed as no ventilation is possible through fixed windows.

Picture window

A very large fixed window in a wall, typically without glazing bars or glazed with only perfunctory glazing bars near the edge of the window. Picture windows are intended to provide an unimpeded view, as if framing a picture.

Multi-lit window

A window glazed with small panes of glass separated by wooden or lead «glazing bars», or «muntins», arranged in a decorative «glazing pattern» often dictated by the architectural style at use. Due to the historic unavailability of large panes of glass, this was the prevailing style of window until the beginning of the 20th century, and is traditionally still used today.

Emergency exit/egress window

A window big enough and low enough so that occupants can escape through the opening in an emergency, such as a fire. In the United States, exact specifications for emergency windows in bedrooms are given in many building codes. Vehicles, such as buses and aircraft, frequently have emergency exit windows as well. [ 3 ]

Stained glass window

A window composed of pieces of colored glass, transparent, translucent or opaque, frequently portraying persons or scenes. Typically the glass in these windows is separated by lead glazing bars. Stained glass windows were popular in Victorian houses and some Wrightian houses, and are especially common in churches.

French window

A French window, also known as a French door is really a type of door, but one which has one or more panes of glass set into the whole length of the door, meaning it also functions as a window. In France, they are known as ‘porte-fenêtre’. In Italy they are very common, usually overlooking a terrace, known as portafinestra (door-window).

Technical terms

The term «lite», or «light», refers to a glass pane, several of which may be used to construct the final window product. For example, a sash unit, consisting of at least one sliding glass component, is typically composed of two lites, while a fixed window is composed of one lite. The terms «single-light», «double-light» etc. refer to the number of these glass panes in a window.

The lites in a window sash are divided horizontally and vertically by narrow strips of wood or metal called muntins. More substantial load bearing or structural vertical dividers are called mullions, with the corresponding horizontal dividers referred to as transoms.

In the United States, the term replacement window means a framed window designed to slip inside the original window frame from the inside after the old sashes are removed. In Europe, however, it usually means a complete window including a replacement outer frame.

The U.S., the term new construction window means a window with a nailing fin designed to be inserted into a rough opening from the outside before applying siding and inside trim. A nailing fin is a projection on the outer frame of the window in the same plane as the glazing, which overlaps the prepared opening, and can thus be ‘nailed’ into place.

In the UK and mainland Europe, windows in new-build houses are usually fixed with long screws into expanding plastic plugs in the brickwork. A gap of up to 13mm is left around all four sides, and filled with expanding polyurethane foam. This makes the window fixing weatherproof but allows for expansion due to heat.

A beam over the top of a window is known as the lintel or transom, while a beam below the bottom of a window is known as the sill plate or windowsill.

In the US, the NFRC Window Label lists the following terms:

• Thermal transmittance (U-factor). Best values are around U-0.15 (equal to 0.8 W/m2/K).
• Solar heat gain coefficient (SHGC) (ratio of solar heat (infrared) passing through the glass to incident solar heat)
• Visible transmittance (VT) (ratio of transmitted visible light divided by incident visible light)
• Air Leakage (AL) (Measured in cubic foot per minute per linear foot of crack between sash and frame)
• Condensation Resistance (CR) (Measured between 1 and 100. The higher the number, the higher the resistance of the formation of condensation.) [ 4 ]