Poor lighting causes eyestrain, inflammation of the eyes and eyelids, headaches, migraine, fatigue and blurred or double vision. It reduces productivity, lowers people's spirits and energy levels, leads to absenteeism and contributes to accidents and injuries in the workplace. Employers have a duty of care to protect their employees' eyesight and related wellbeing. The 1993 Regulations on the Safety, Health and Welfare at Work Act 1989, state that places of work should receive sufficient natural light and be equipped with artificial lighting "adequate for the protection of employees' safety and health".
Workers should not experience discomfort caused by brightness, shading, glare or reflection due to inadequate or poorly placed light sources or workstations.
Employers are obliged to assess whether lighting is sufficient and appropriate for all the tasks performed at every workstation. Any glare, flicker, shadow, reflection or any stroboscopic effect should be identified and eliminated.
Glare should be eliminated because it can distract people, cause discomfort and restrict people's vision. Flicker must be dealt with because it induces fatigue and could even trigger an epileptic fit. Reflection on work-surfaces or computer screens reduces productivity, increases the likelihood of errors and can cause muscular-skeletal problems when employees adjust their posture to counteract it.
Tungsten halogen lamps the kind found in many desktop lamps and high intensity discharge lamps can emit significant ultraviolet radiation which can damage the skin and cornea of the eye when used "close to people (i.e., within a metre or so) for extended periods", according to the British Health and Safety Executive (HSE) in its publication Lighting at Work. The HSE recommends that where these are used they should be fitted with an ultraviolet filter and, if the luminaire has no filter, "it should not be used for close-work applications". Care should also be taken to keep flammable objects away from these lamps.
Irish regulations state that emergency lighting must be provided if "in the event of failure of artificial lighting" employees would be exposed to risks to their health and safety.
Moreover, lighting installations must be "placed in such a way that there is no risk of accident to employees as a result of the type of lighting fitted".
Lighting at work should be such as to enable workers to determine colours, especially in electronic assembly work or with any electrical work. Light should also meet the individual requirements of employees with special needs. There should not be a radical difference in illuminance within a work area or between adjacent work areas. Differences in illuminance can cause visual discomfort and increase the likelihood of accidents, especially where there is frequent movement.
Employers must detail on the company Safety Statement, any health and safety risks associated with lighting and they should eliminate, reduce or control such risks. They need to ensure lighting is properly maintained and that faulty or damaged lighting is dealt with promptly.
Lighting can be divided into three kinds: general lighting illuminates the entire workplace uniformly; localised lighting applies varied lighting levels at different workstations; while local lighting provides high illumination close to the point of work.
Each product has recommended ratios for the relationship between spacing and mounting height.
The angle of the luminaire is also important. For instance fluorescent lamps emit less glare if viewed end-on rather than from the side. If it is not possible to change the position of a light source or workstation, VDUs should be equipped with anti-glare screens to reduce glare or reflection from natural or artificial light.
