Two thin lenses of power + 4D and –2D are in contact.

power 4dTranscript. Question 39 If the power of a lens is − 4.0 D, then it means that the lens is a (A) concave lens of focal length −50 m (B) convex lens of focal length +50 cmThe latest in indoor personalized training, the Sufferfest takes you into the 4th Dimension. Their new Four-Dimensional Power training takes an individually optimized