The 1970's
Technology and society determine how we work – and therefore the further development of the office. Today's work places different demands on lighting than the paper dominated work of 50 years ago. Lighting design at that time also focused on people, their perception and visual needs. In offices of the 1970's these consisted mainly of horizontal visual tasks. Traditional lighting methods at that time such as planar lighting for both the desk and surroundings that was typical of fluorescent lamps now only seldom meet the needs of today's visual tasks at desks.
The 1990's
The advent of computers triggered a transition from horizontal to vertical visual tasks – in some cases still with a spatial separation at the workstation. Narrow distribution luminaires were used to achieve suitable visual comfort for the very first monitors with highly reflective screens and poor contrast conditions. This however led to dark ceilings and wall areas, and perception of the room also suffered.
Today
The design and equipping of today's modern office workplaces aim at ergonomic work with computers. The monitor representing the vertical visual task is focused on. Work with paper is limited to hand-written notes at most workstations. Horizontal, zonal general lighting provides uniform light for the workstation but no longer has the function of rendering small details visible across large areas.
The right light for computer work
With most computer supported work, the backlit monitor is the primary light source. There is no further need for horizontal general lighting with nominal illuminances of 500lx. Local higher illuminances, for example to modify brightness for the individual's requirements can be much more efficiently achieved by using local task lights. Illuminated vertical surfaces and bright ceilings still remain essential for the perception of brightness. As a consequence, wallwashing and ceiling washlighting are essential components of the zonal lighting of office workplaces.