LightSensor is a non-visible component that measures the ambient light level (illumination) in lx.
Event-handler block. Event is triggered when a sensor change occurred
LightSensor includes following properties-blocks. They allow you to determine if user's device has this type of sensor or enable / disable this sensor.
In Screen initialize , you can check if LightSensor is available or not. You can use block LightSensor.LightChanged to determine the sensitivity of light changed in lx unit: