1. An optically transparent element comprising: an optically transparent substrate; and an anti-reflective coating disposed on at least one surface of the optically transparent substrate, the anti-reflective coating comprising a polymer, the polymer comprising: at least one first tetraalkoxy silane residue; and at least one second alkoxy silane residue selected from the group consisting of trialkoxy silanes, dialkoxy silanes, monoalkoxy silanes, and combinations thereof, wherein the polymer comprises at least 50 mole percent of the at least one tetraalkoxy silane residue based on the total moles of polymer.