1. The problem statement, all variables and given/known data A glass lens (n=1.50) in air has a power of +5.2 diopters. What would its power be if it were submerged in water? 2. Relevant equations Not too sure. May be Lensmaker's Equation, Snell's Law, and Power of a Lens Equation. 3. The attempt at a solution I'm trying to derive the Lensmaker's Equation with the surrounding substance having index of refraction 1.33 but that didn't work. I also tried changing the index of refraction of the lens so that it was with respect to the speed of light in water rather than in air.