Abstract: In order to extend the life of a light source such as a CCFL or the like being used in backlighting system for an LCD, the present invention includes an optical sensing circuit, an amplification circuit, an averaging circuit, a comparator circuit, a controller, and an inverter dimmer circuit. The initial power applied to the light source is limited to a value which is less than its maximum rate power thus reducing the rate of light source degradation geometrically. The brightness of the light source is monitored using a photosensitive element/sensor, and as the brightness reduces with the passing of time, the power that is supplied to the light source is gradually increased. This both prolongs the life of the life source and obviates any perceivable reduction in display brightness.