What is meaning of +- 4D in eye for job application requirement

power 4dGiven, Power of convex lens=4D. Placed at 40 cm from a wall. To Find, Distance of a candle. Solution, It is given that ,Power = 4D. Then, P = 1f. So, 4 D = 1f4D History - Check 4D number past winning history since 1985. 4D Number Pemutation. mBox, iBox, i-Perm Source . Date From. Date To. Disclaimer