In physics, intensity is described as the power transferred per unit area and its unit in the SI is watt per square metre (W/m2). As a result of that, any increase in distance from the originating source of energy, or in this case, a source of light, would decrease the intensity of the object. The shorter the sitting distance is, the brighter the light source would appear and at the same time, as the sitting distance becomes longer, the light source would appear to be of lower brightness.
