Tinting does vary from state to state, but I do recall a previous post here that had a window tinting installer's web-site. That site linked to a list that had all the different tinting laws for each state and what could be done. If I recall correctly, there was not a single state where tinting the windshield was allowed. The only thing I remember was that the very top part of the windshield could be tinted if, as another poster mentioned, the proper documentation was received by a medical specialist. Otherwise you can't do it. Also know that tinting laws also differ from vehicle to vehicle... in other words, there are different laws for cars, suvs, and trucks...