For satisfactory vision the minimium illumination accepted is -: (A) 15 to 20 foot candles, (B) 30 to 40 candles, (C) 40 to 50 candles, (D) 70 to 90 candles
Answer is A. An illumination of 15 to 20 foot-candles is accepted as a minimum basic requirement for satisfactory vision. 1 FC = 10.76 Lux Park's Textbook of Preventive and Social Medicine, 25th Edition, Pg 799