The UGR value is a unitless number that shows the magnitude of the blinding and dazzle sensation of indoor lighting. UGR values should be determined step by step in the range of 10 to 30. The levels determined according to DIN EN 12464-1, 13, 16, 19, 22, 25 and 28 express a sense of statistical dazzle to many observers. The lower the UGR value, the less the observer experiences an unpleasant, blinding dazzle sensation. Different activities have different regulations on glare: Technical drawing: UGR≤16 Reading, writing, classrooms, computer work, inspection work: UGR≤19 Industrial and craft work, reception: UGR≤22 Work, stairs: UGR≤25 Corridors : UGR≤28