Glare: how to stop bright light from dazzling you

Glare comes not from too much light but from the way light reaches the eye. How to recognise the causes and fix them, often without changing the lamp.

You fit a new LED lamp, the room is brighter, yet when you lie on the sofa you find yourself squinting. A white patch shows up on the computer screen, and looking up in the kitchen is uncomfortable. That is glare. More often than not it has little to do with the total amount of light in the room: the problem is how the light reaches your eyes.

Two kinds of glare

Specialists usually distinguish between two situations.

Discomfort glare. Your vision is not impaired, but your eyes tire, you squint and turn your head away. Sitting in this light for long periods can lead to headaches and tension.

Disability glare. A strong bright source scatters light inside the eye, so details around it disappear. The headlights of an oncoming car on a dark road are a familiar example.

At home the first kind is more common, but it still significantly reduces long-term comfort.

The main causes

• A bare lamp in your line of sight. A pendant with no shade, a bulb visible below a lampshade, a wall light at eye level.
• A small, very bright source. The same light is comfortable coming from a large surface and harsh coming from a tiny point. Clear filament lamps and exposed LED chips are more prone to this.
• Strong contrast. A bright screen or a single bright lamp in a dark room is hard on the eyes, because they try to adapt to two very different brightness levels at once.
• Reflections. A glossy tabletop, glass, polished tiles and monitor screens send the lamp's reflection straight into your eyes.
• The wrong beam angle. When a narrow-beam spotlight is aimed at a sofa, bed or seat, you end up looking straight into the beam.

What you can do without changing the lamp

Getting rid of glare often does not require a new lamp.

• Move the light out of direct view: raise the pendant or use a deeper shade so the bulb cannot be seen from the side.
• Increase general background light in the room. When the contrast created by a screen or a single lamp drops, the same brightness bothers you less.
• Turn adjustable spotlights towards a wall or the ceiling. Reflected light is softer and spreads more evenly.
• Take glossy surfaces into account: position the monitor relative to windows and lamps so that reflections do not land on the screen.
• If there is a dimmer, lower the light in the evening; when the eyes have adapted to darkness, the same brightness feels harsher.

When choosing lamps and fittings

If you are making changes, look at the following:

• Frosted bulbs. At eye level or in open fittings, a frosted lamp spreads light over a larger surface and hides the bright point.
• Diffusing shades. Opal glass or frosted acrylic softens brightness.
• Deep-set spotlights. Models in which the lamp sits deep inside the housing keep the source out of sight from the side.
• Wide beam angle. Use wide-beam lamps for general light and keep narrow beams for accents only.
• Colour temperature. In a dark evening room, very cool light looks harsher to some people; warm or neutral light is usually more comfortable in living spaces.

Glare in workplaces

In office lighting, glare is assessed with a dedicated figure, the UGR. The EN 12464-1 standard recommends a UGR of 19 or lower for offices where people write and work at computers. The value appears in the luminaire manufacturer's data sheet and is calculated for a specific room. No such calculation is needed at home, but the principle is the same: bright sources should sit outside your field of view, and light should come from larger surfaces.

A quick check

Sit in the places you normally use and look around. If you can see a bare lamp without raising your head, if there is a reflection of light on the screen or table, or if there is a sharp difference between the lit surface and the background, you have found the source of glare. Sometimes moving the lamp by ten or fifteen centimetres is all it takes. Do the check in the evening with all the usual lights on rather than in daytime, and in a child's room look from the height at which the child sits and lies.

The adjustable 3D spotlight in Zaferoğlu Elektrik's range lets you change the direction of the light; pointing such a spot away from seating, towards a wall or a work surface, is a simple way to prevent glare.