Exterior and interior lighting should be directed to avoid glare and reflection and to maintain a consistent pattern and level of light. The type and placement of lighting should never cause the shadowing of building elements that need to be seen.
Consistent use of different types of lighting can provide useful directional cues and help people with vision loss differentiate between areas in a space. For example, one type of light can be used to light pathways and another type can be used for parking lots.
Here is a checklist for good lighting placement:
- Avoid glare. Glare and reflection, often caused by shiny or glossy surfaces, can cause visual confusion. Check light fixtures from all angles at their proposed mounting height to identify glare-producing surfaces, and then make any necessary adjustments to the lighting or the surfaces.
- Place light sources to avoid creating problem shadows. Shadows, whether caused by natural or artificial light, can hide important features and create optical illusions. For instance, a shadow can appear to be the edge of a table or part of a building, or it might hide an obstruction from view.
- Distribute light levels evenly at working and walking surfaces. Changes in lighting levels from one space to the next (such as an elevator to a corridor) should not exceed a range of 100 – 300 lux.
- Include task and spotlighting to augment the overall lighting system. This is an economical way to provide extra light for certain areas without having to light the entire space brightly. Task lighting benefits everyone and is essential for people with vision loss who require extra light for detailed tasks such as reading and writing.
- Use dimmer switches and high-wattage light bulbs whenever possible and appropriate so that lighting levels may be adjusted to suit the needs of different users of the space.