Human-centric lighting: Anti-glare lighting

Recognising glare and how it affects those who are exposed to it is an important aspect of human-centric lighting. How can knowing how lighting affects its users influence our product choices and layout design? Grab your sunnies because we’re about to take a direct look at the sun to gain a better understanding of glare.

Blinded by the light: Glare and its downsides

Glare happens when a light is too intense for our eyes to adapt to its brightness, and can come from a light source or a reflection. A simple example of this dazzling sensation at its most unpleasant is when driving into the sun; not only is it uncomfortable, but potentially dangerous if you need to shield your eyes. Though subjective, most light sources will give off at least minimal glare, but when vision is disturbed by extreme brightness, we need to improve conditions.

Research has identified two key types of glare; discomfort glare, which can cause pain but not necessarily visual impairment, and disability glare, which is the scattering of excessive light that enters our eyes and does lead to visual impairment. Think back to the scenario of staring into the sun. If you don’t get a chance to look away, it can be quite painful and when you close your eyes you’ll see coloured spots each time you blink. (In very basic terms, this is the eye and brain’s way of forcing themselves to process the excess light.) Imagine living or working in conditions with prolonged exposure to glare like this. Even with the less extreme discomfort glare, you’ll likely experience reduced concentration, work performance and frustration, along with physical ailments such as headaches, visual fatigue, sore eyes, and impaired vision*.

An example of designing a human-centric layout. Someone is less likely to be dazzled by lights within their field of vision and would only be affected if they stood directly beneath a luminaire and looked straight up into it.
An example of designing a human-centric layout; someone is less likely to be dazzled by lights within their field of vision and would only be affected if they stood directly beneath a luminaire and looked straight up into it.

Diffuse the situation: Anti-glare products

The main feature of anti-glare luminaires is that the optic or lens is designed to diffuse light, as opposed to common household lamps that use a polycarbonate diffuser that become a source of glare. Good quality prismatic surfaces distribute light evenly and smoothly by acting as a primary reflector, a bit like how sunscreen works. Some anti- or low-glare lights incorporate a fascia, frame or secondary reflective cover to act as a shield, similar to putting on a hat. Unlike hats, they direct the light beam toward the desired location and, importantly, away from people’s field of vision. Furthermore, filters, honeycombs, louvres and other such specialty add-ons are available in a variety of angles, shapes and positions for tailored anti-glare lighting. Think of these as wearing a pair of sunglasses.

Our Timbre range can be customised with specialty components like filters, honeycombs and louvres. 10W Vega track lights. Prismatic anti-glare lens on Melba downlight.
Left: Our Timbre range can be customised with specialty components. Middle: 10W Vega track lights at Ned’s Local European. Photography by On Jackson Street. Right: Note the prismatic anti-glare lens on our Melba downlight.

Off the wall: Repositioning light sources

Another way to think about countering glare for a more comfortable or productive environment is to consider moving the luminaire from sightlines as with uplighting. This is when a lamp faces upwards and bounces light off the wall and ceiling around the room. In a way, the ceiling acts as a giant reflector that softens the light and provides gentle illumination. Typically, uplights as an anti-glare remedy are installed above eye level so the light source isn’t visible. This can be achieved with wall lamps, floor lamps or adjustable ceiling fixtures.

The Bellucci wall light faces upwards for soft illumination. Module B from our Boulevard collection can be cleverly installed as an uplight for anti-glare lighting.
Left: The Bellucci wall light faces upwards for soft illumination. Photo courtesy of Hallbury Homes. Right: Module B from our Boulevard collection can be cleverly installed as an uplight.

One final recommendation is to be mindful of highly reflective surfaces and whether they’re contributing to the glare in a space. If possible, cover, angle or relocate surfaces if you can’t adapt your existing lighting.

When combatting glare, the goal is to experience the light without seeing its source. Just as natural light is optimal when the sun isn’t dazzling your eyes, the same goes for artificial illumination. Using a combination of human-centric solutions will work together to provide the most comfortable environment to work and relax in.

 

*There is plenty of research into glare and its effects on humans. Some interesting examples are:

• the book Human Factors in Lighting by Peter R. Boyce, 3rd edition 2014;
Lighting and discomfort in the classroom by Mark Winterbottom and Arnold Wilkins, published in Journal of Environmental Psychology, March 2009;
• and Overview of glare types and their relationship with macular pigment optical density by Christopher M. Putnam, published in International Journal of Advanced Research, August 2017.