In an office environment, it is important to consider both the overall lighting level and the position of lights and windows. For computer work, excessively bright lighting can cause visual discomfort, especially when it creates glare on the computer monitor. Inadequate lighting can also result in eye strain particularly when working with paper documents. Compared to computer work, paper-based work often requires a higher lighting level, such that additional task lighting may be necessary. Older workers may need a higher lighting level to compensate for visual limitations due to age.
Glare occurs when there is a large difference in light levels within the visual field. Glare can lead to visual fatigue and discomfort as the eyes try to adapt to the differences in light levels. You may also adopt an awkward body position in order to avoid either direct or indirect glare.
Direct glare occurs when a source of bright light, such as a task light or an unshaded window, is directly in your field of view. Indirect/reflected glare occurs when light bounces off nearby surfaces into your field of view. Both types of glare can be distracting and impair your ability to view the computer monitor.
To optimize the office environment with respect to lighting, the following should be considered: