People with some types of vision loss have difficulty adapting to sudden changes in light levels. In some cases, it may take a few hours for a person with vision loss to adjust to a dramatic change in lighting. For this reason, the level of illumination provided by emergency lights should ideally match the usual light levels in the building.
Emergency lighting is meant to be a temporary light source and is not intended to illuminate entire areas. However, where emergency lighting is essential to provide a visual cue leading towards an exit or area of safe refuge, then the normal illumination levels for that space should be maintained during an emergency situation.
An added benefit to providing a level of emergency lighting that exceeds the minimum building code requirement of 10 lux (average at floor or tread level) is that it has the potential to increase visibility in smoke-filled areas.
Avoid directing light towards the direction of travel. Glare or light directed at pedestrians can cause problems for some people with vision loss.
Use photo-luminescent strips along baseboards and stairs to lead people to emergency exits. This lighting is also recommended to highlight features such as door frames and telephones in areas of safe refuge.