Created on: 14 Jul 2023
Inadequate lighting at work can lead to eye strain, fatigue, headaches, stress and accidents.
The amount of light is not the only factor as badly designed lighting systems give rise to glare. This can cause stress and headaches, as well as creating accident risks.
Heavy contrasts can be dangerous as moving between bright to very dark areas can cause temporary blindness as the eyes adapt.
Common lighting problems found at work include:
Lighting problems at work can be investigated in a number of ways:
The level of light is measured in “lux”. Interior levels are very much lower than outdoor natural light. Some typical light levels are:
Very bright summer day
up to 100,000 lux
Overcast summer day
30,000 to 40,000 lux
‘Bad light stops play’
Shady room in daylight
The amount of light can be measured by a light meter.
These are readily available, though many photographic light meters are not calibrated in lux.
The employer’s duty to ensure the health, safety and welfare of employees under HASAWA includes a duty to provide adequate lighting to ensure that work can be done safely and employees’ health or eyesight is not damaged.
The provisions contained in MHSWR, especially Regulation 3, risk assessment, are also relevant. Regulation 8 of the Workplace Regs states that employers must ensure that:
The Regs do not define “suitable and sufficient” but the ACoP says that the lighting should enable people to work and move about safely and will be dependent on the tasks to be performed and hazards to be negotiated. Where natural light is utilised, windows and skylights should be regularly cleaned, although they may be shaded to reduce glare and heat.
If emergency lighting is necessary for reasons of safety, it should be powered by an independent energy source to the artificial lighting. Lighting should be sufficient to enable people to work, use facilities and move from place to place safely and without experiencing eye-strain. Outdoor areas should be adequately lit after dark.
Lighting levels may be adequate but glare from a direct source or light reflected off equipment or paper can cause discomfort. Glare is light in the ‘wrong place’ and there are three different kinds.
All can cause strain and fatigue and some may interfere with vision:
The best way to spot the effect of glare is to identify places where a light source shines directly or by reflection into the operator’s vision. It can be harder to spot glare from light fittings when day light is present as well.
Then see if screening, shading or fitting diffusers on lights makes any difference. To reduce glare the following steps should be considered:
It is important to get lighting arrangements right at the design stage for example when new work layouts are being planned. Some key principles are:
Even well designed lighting systems will not perform properly unless well maintained. Dirty fittings can produce a light loss of 20%. Old fluorescent tubes can lose up to half their brightness before they fail. Bulbs lose 10% brightness before failure.
Old light units are less economical because they use the same current to produce less light. It is better to replace lamps in a group in all but small lighting systems. This can be more economic and less disruptive than replacing individual units as and when they fail.
A regular cleaning programme for fittings is also sensible.