Here, we'll describe problems bad lighting can create and suggest ways to reduce or prevent these problems by changing lighting techniques. Inappropriate lighting is at the root of many work-related vision problems, contributing directly to eyestrain symptoms of headaches and decreased visual efficiency and often leading to increased frequency of errors. Can create discomfort, and fatigue results when eyes must adjust and readjust to accommodate two very different light levels. Can obscure portions of text and render graphic illustrations or photographic images difficult to read. One example is directional lighting that falls onto a person's head or writing hand that creates shadows on horizontal work planes, obscuring reading or writing materials.
Overhead cabinets extending over the work surface also create areas of shadow and contrast.
When the eyes must continually adjust between different levels of brightness in tasks or surroundings, they work harder and tire faster than in environments where shadows are diffuse and brightness levels relatively uniform. People will sometimes assume awkward positions to avoid a direct glare source or a hot spot on a computer screen, which can result in neck, shoulder or back pain and may lead to repetitive strain injuries. Overhead glare can contribute to the problem. Often caused by harsh shadows and high contrast. Interior spaces that are sufficiently illuminated for computer-intensive office or study tasks may still feel dim or gloomy to the people who work in them.