Human eye can adapt pretty well and quickly to different lighting conditions, but some tasks in the workplace have recommended levels of lighting in order to reduce the demand on our eyes and the need to adapt quickly and often to different tasks and viewing fields.
To follow, a summary of the Office health and safety WorkSafe guide advice on lighting levels and quality of light.
Quality of Light
The quality of light refers to the lighting level and other factors that influence how effectively tasks can be performed. Key factors include:
- Number of lights: Using the correct number ensures consistent lighting across the area.
- Type of lights: Options include LED, fluorescent tubes, compact fluorescent, tungsten, and halogen. LEDs are energy-efficient, using about 75% less energy than halogen bulbs and lasting five to ten times longer.
- Light fittings: The design of light fittings affects the direction of illumination.
- Light positioning: Lights should be strategically placed to adequately illuminate workstations.
- Color rendering: How colors appear under the lighting impacts visual comfort.
- Maintenance: Regular upkeep ensures optimal lighting conditions.
- Sunlight: Features like skylights, transparent roof panels, or light tubes can maximize natural light for internal spaces.
When planning office lighting, employers should consider these factors and consult a lighting designer when designing a new workspace.
Natural Light
The time of day and year affects the amount and quality of natural light in work areas. Natural light may create issues, such as glare or inconsistent brightness. Providing adjustable features like venetian or vertical blinds allows employees to manage natural light effectively.
Color
The choice of colors in a workspace impacts the mood and light reflection:
- Ceilings: Should reflect around 80% of light, typically painted white or off-white.
- Walls: Should reflect 50%–75% of light, using subdued cool colors with a gloss or semi-gloss finish.
- Floors: Should reflect less than 20% of light, with darker, non-glossy finishes preferred.
- Decor: Adding colorful posters or non-reflective artwork can reduce monotony and provide visual variety.
How Light is Measured
Light levels in a workspace can be measured using a light meter, also called a lux meter. This device determines:
- Overall light levels in a specific area.
- Illuminance, which refers to the amount of light reaching a surface, measured in lux.
The recommended illuminance for various work activities is outlined in AS/NZS 1680.1:2006 – Interior and workplace lighting, Part 1: General principles and recommendations. These recommended levels provide approximate guidelines for different types of work environments.
Common hazards and issues
Glare in the Workplace
Glare occurs when one area is significantly brighter or darker than its background. For instance, a bright window positioned behind a computer screen can create a stark contrast, forcing the eyes to constantly adapt. This strain may lead to eye fatigue, headaches, and difficulty viewing the screen clearly.
To minimize glare, consider the following strategies:
- Control natural light: Use adjustable blinds to manage the intensity of sunlight entering the workspace.
- Reduce contrast: Opt for slightly darker, matte-finished partitions to minimize the disparity between a computer screen and its surroundings.
- Reposition workstations: Adjust the layout to limit direct light on work surfaces.
- Adjust general lighting: Lower overall lighting levels to better suit the task at hand.
Flickering Lights
Malfunctioning lights, especially older fluorescent tubes, can be a source of irritation and pose potential health risks. Flickering or flashing lights may trigger seizures in individuals with photosensitive epilepsy.
Lighting should enhance the visual environment by being free from flicker, stroboscopic effects, and glare. Regular maintenance is essential to minimize flickering issues and maintain consistent illumination.
Stroboscopic effects, in particular, can create hazardous illusions with moving or rotating machinery. They may cause equipment to appear to:
- Move slowly
- Move in reverse
- Appear stationary
Such illusions can lead to workplace accidents. To prevent this, lamps should be wired to eliminate stroboscopic effects.
Shadows on Work Surfaces
Shadows can:
- Reduce visibility.
- Add to glare.
- Lead to poor posture.
To check for shadows, hold a piece of paper above the work surface or observe if shadows affect visibility or posture.
Ways to reduce shadows include:
- Increasing and spreading overhead lighting.
- Moving the work or its position.
- Redirecting light.
- Removing or relocating barriers blocking light.
Adjustable task lamps can help when:
- Shadows persist.
- Directional lighting is needed.
- Increasing general lighting isn’t practical.
However, task lamps can create light pools that strain the eyes. Where possible, removing barriers to light is the best way to eliminate shadows.
Posture and the Visual Environment
When visibility is poor, employees may:
- Lean closer to the task.
- Bring the task closer to their eyes.
These habits can lead to awkward postures. If poor posture occurs, issues like shadows, glare, or reflections may be contributing factors.
Employees reporting discomfort should be observed during their regular tasks. A neutral, well-supported posture helps reduce discomfort.
Common causes of poor posture include:
- Inadequate lighting.
- Poor screen design or placement.
- Uncorrected vision problems.
If lighting is a factor, assess:
- Are shadows cast over the work area?
- Is there enough light for the task?
- Are glare or reflections affecting posture?
For potential vision issues, seek advice from a medical specialist or optometrist.
Consultation
Remember that the employer has a duty to consult with employees and Health & Safety Representatives (HSRs) on every issue concerning the workplace. Find more information about consultation here Consultation - what does the employer have to do? - OHS Reps.
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Published January 2025