Task lighting is area-specific lighting that increases the light intensity over a smaller area such as source documents, books, or other written materials. Good task lighting should be adjustable in direction and brightness. Task lights should be arranged so bulbs are not in direct field of view. Task lights should be positioned so that the bulbs are well shielded. Use dark, opaque shades for desk lamps rather than sheer, light colored shades.
Ambient lighting is the general room lighting that is typically supplied by overhead fixtures.
Ceiling-mounted fluorescent lights can offer direct lighting or indirect lighting. Indirect light is light that is directed at the ceiling or a wall and showered down onto the work area. Indirect ambient lighting is typically more comfortable for the eyes than direct lighting, and results in fewer shadows as well as less reflection on computer screens. Computer users should maintain low ambient lighting levels. When working alone, dim or turn off overhead lights.