According to the international standard, the illuminance required for reading is about 500 to 1000 lux, and the illuminance required for designing and handicraft work is about 1000 to 2000 lux. Working below or reading under illuminance conditions the required level may cause eyestrain.The traditional 27W FL desk lamps in the market can generally provide a sufficient illuminance for eyes, while the illuminance from a 13/18W FL desk lamp is appear ently not sufficient as sole light source for reading.