A method of determining exposure of an occupant to equivalent melanopic lux, EML, in an environment comprising one or more illumination devices (4, 5), wherein said one or more illumination devices (4, 5) comprise one or more luminaires illuminating the environment with artificial illumination, the method comprising accessing light level information from one or more information sources (6, 12), and based thereon determining where in said environment at least a predetermined EML level is present; using a tracking system to track the occupant within said environment; and based on said accessing and said tracking, monitoring whether the occupant has been exposed to at least a minimum EML quota, the minimum EML quota comprising the occupant being exposed to at least said predetermined EML level for at least a predetermined time constraint wherein said predetermined time constraint comprises at least a requirement that the occupant is exposed to said predetermined EML level for a minimum period of time within a predetermined time window of a day, a working day, the hours of daylight in a day, or a morning between 9am and 1pm; wherein the time constraint resets each day; wherein the one or more information sources comprise a database and said light level information comprises data from the database mapping out light level values indicative of EML in said environment and resulting from said one or more luminaires, wherein the light level values are pre-calculated or pre-measured and obtained during a pre-performed calibration of the one or more luminaires during an installation or commissioning phase, said determination of where in said environment at least a predetermined EML level is present being based at least in part on the light level values. accessing light level information from one or more information sources (6, 12), and based thereon determining where in said environment at least a predetermined EML level is present; using a tracking system to track the occupant within said environment; and based on said accessing and said tracking, monitoring whether the occupant has been exposed to at least a minimum EML quota, the minimum EML quota comprising the occupant being exposed to at least said predetermined EML level for at least a predetermined time constraint wherein said predetermined time constraint comprises at least a requirement that the occupant is exposed to said predetermined EML level for a minimum period of time within a predetermined time window of a day, a working day, the hours of daylight in a day, or a morning between 9am and 1pm; wherein the time constraint resets each day; wherein the one or more information sources comprise a database and said light level information comprises data from the database mapping out light level values indicative of EML in said environment and resulting from said one or more luminaires, wherein the light level values are pre-calculated or pre-measured and obtained during a pre-performed calibration of the one or more luminaires during an installation or commissioning phase, said determination of where in said environment at least a predetermined EML level is present being based at least in part on the light level values.