Growing up our parents drilled into our heads, “Don’t read in the dark. You’ll strain your eyes”.
The way many office building and retail owners over-illuminate their spaces, you would think they were told the same thing. Well, is there such a thing as too much light?
Along with not getting the look you want in a space, as well as wasting energy, there are some health side-effects to having too much light in a space—the most common being frequent headaches. Over-illuminating can have negative impacts on the people who occupy an overly bright space. Too much light will lead to eye-strain, migraine headaches, even fatigue and stress.
Per the Illuminating Engineering Society of North America (IESNA), for typical office tasks (reading, etc.), the recommended average foot-candle (fc) level is 30-40. In certain circumstances (mainly due to age of the occupant), this may not be enough. However, additional task lighting can be provided that the user can control.
The old-way of thinking was that an office space needs at least 70 fc or more, but this is no longer the norm. One size, or method, does not fit all. Purposeful design requires a deeper understanding of the “whys” and the “hows,” and rules of thumb only serve to dehumanize the process. Designing a space with good general and also good task lighting will help occupants and the customer be more comfortable and have a much better experience. Too much light is very often the result of too little knowledge.