Lighting and Visual Performance

Visual performance is highly dependent on contrast, meaning that an observer should easily be able to separate an object from its surroundings. For this to happen the brain uses brightness perception, which is highly dependent on previous experiences and the brain’s expectation as an output for it to understand what’s happening in its surrounding environment.
With proper conditioning of light, we can make it easier for observers to focus and perform tasks, we’ve tested some lighting conditions in the office and here are there results

As designers, we can create the needed contrast for optimal visual performance, by creating comfortable contrast for observers. We do this by using a luminance ratio (brightness difference), there are no actual specific values for this ratio, since we can usually estimate it according to our own perception, but we should always care for it properly. If the ratio between the task and the space is nearing to even, that means the space is possibly too brightly lit, which them diminishes contrast and makes it difficult to understand the task. In such a case, the eye is not able to adapt to send the correct signals to the brain (in this situation the luminance ratio is nearing 1:1, where there is no apparent contrast).
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