Between 300 and 500 lux
According to the International Compensation on Lighting, the optimum lighting for regular desk work is between 300 and 500 lux. This is the standard that many office buildings aim for, as it offers enough light to see plainly without creating eye stress. Nevertheless, there are some circumstances where the lux level should be higher or reduced. For example, when servicing accuracy tasks, a higher degree of light might be necessary to minimize errors. Likewise, it is important to ensure the luminance is not too low when operating in dark illumination conditions, as this can trigger eye fatigue. In general, however, a lux level between 300 and 500 is perfect for most office work.