What is task lighting, why do we need it, and how does it relate to ergonomics? If this term is foreign to you, these might be questions that spring to mind.
Task lighting, put simply, is a light source – often small and portable – designed to provide illumination for a specific fixed task, as opposed to the general area lighting present in every office building and indoor industrial workplace. There is nothing new about the concept; it actually dates back before the invention of the electric light bulb.
Certain professions are often identified with task lights, such as an architect sitting at a drafting table with a clamp-on, adjustable halogen lamp providing plenty of illumination for drawing and plan details. In traditional offices, task lighting has been an option for some, often integrated into the workstation cubicle. But as overhead lighting systems were designed to provide ample illumination for all general office tasks, use of task lighting was not that widespread.
The computer effect
With increased computer use in the last couple of decades, lighting demands have changed. For most office workers, the focus is now on the computer monitor, an additional source of light. Because of this, lighting experts began to recommend lower levels of illumination for general lighting in offices to reduce glare and to make viewing these monitors easier on the eyes. As computer use continues to evolve, businesses strive to go “paperless”, where all documents are electronic and accessed via computer. Because the technology has not been fully adopted by many businesses, the need to read hard copy and work from source documents remains widespread. And here is where the need for task lighting comes in – lower light levels needed for viewing the computer monitor, higher levels for looking at hard copy and source documents – needs that can really only be met with adjustable supplemental lighting. ANSI recommends about 30 foot candles of background light for monitor viewing, and about 50-100 foot candles when working from hard copy materials.
Be careful of too much light
Excessive office illumination levels lead to glare on computer screens. As users adjust their positions to minimize the glare, awkward postures are sometimes adopted. The benefit of task lighting is to provide a small area of concentrated light which will not interfere with the monitor screen, and allow users to comfortably view other documents. Office cubicles with built-in task lights can result in additional glare, known as a veiling reflection, if located directly in front of the user. Portable, adjustable task lights are the preferred source of lighting due to their versatility. Available in incandescent, halogen and fluorescent formats, when properly adjusted, the light can be directed from either side of the user rather than directly in front, minimizing the potential for veiling reflections.
Who needs task lights? As we get older, our eyes need more light, especially for precision tasks, making task lighting necessary. In the office, anyone working from source documents or who may perform hand-written tasks may need additional lighting so task lights are appropriate. New breakthroughs in LED (light-emitting diodes) technology are now beginning to enter the task lighting market. The use of LED technology is gaining more acceptance in both office and industrial task lighting as it offers the advantages of longer life and lower power consumption, while producing a strong, dimmable white light.
Cornell University has developed a useful task lighting evaluation form to help you choose the best type of task lighting for your application.