Which applications, either for diagnostic purposes or for therapeutic purposes, involve radioactive materials placed in the body? check all that apply. radiopharmaceuticals mri laser eye surgery external beam radiation therapy lithotripsy brachytherapy radioisotope imaging

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90