Look around and take a note of the following key points
How is entire space lit? Does it feel pleasant and spacious? Do walls look bright enough? Any dark spots?
Any lighting controls installed ? If so, are users satisfied?
Enough light on desks to minimize eyestrain?
Disturbing screen glare due to lighting , according to users ? Are low glare luminaires used (UGR ≤ 19)?
Controls
Display reflections
Illuminance
requirements