Being an ocularly challenged reenactor myself, I wondered the same things.
First, glasses, while probably not as common as today, were worn by a great many people in the 1800's. They were stigmatized as a sign of weakness, despite the popular image of Ben Franklin wearing spectacles.
Second, tinted lenses were not at all common, and should be avoided by reenactors. Usually (though not always) tinted lenses were used as a type of medical therapy for a variety of ailments including, but not limited to venereal diseases.
Third, period frames, in remarkably good condition, can still be purchased at antique shops for less than $50.00. Choose oval or rectangular frames (round and octagonal frames are from the 1960's to present day) WITHOUT nose pads. Also stay away from the wrap-around ear wires. Wings on period glasses had either flattened tips, or loops into which cotton cording was once tied, acting like 19th Century 'Croakies.'
Finally, try using contact lenses. It gives you one less thing to worry about at a reenactment.