A convex lens of power +4 D is brought in contact with a

power 4dThe latest in indoor personalized training, the Sufferfest takes you into the 4th Dimension. Their new Four-Dimensional Power training takes an individually optimizedA convex lens of power 4D is kept in contact with a concave lens of power 3D, the effective power of combination will be . View Solution; Knowledge Check. A convex lens of focal length 40 cm