"In order to eliminate glare from a horizontal surface such as water, what is the orientation of the polarizing axes in polarizing sunglasses?"

Answer

Polaroid sunglasses with transmission axes that are oriented vertically so the glasses absorb the horizontally polarised light and as the glare is composed of that orientation of light they therefore reduce the glare.

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.