Another alternative to a motorcycle visor is to search for polycarbonate (more durable, more expensive) or clear plastic sheets (less costly, easier to crack/split/break). If you go for polycarbonate, I wouldn't advise going any thicker than 1/16th of an inch (roughly 1.6 mm) as it will be far more difficult to shape. If it doesn't bend easily or retain its shape you can heat it with a heat gun, hair drier (not as effective) or very, very carefully use an oven on very low heat (wouldn't advise this, though, and if you do use this method would be best to not be using the same oven you cook food in). You can sometimes find these sheets pre-tinted, or you can go clear and use automotive window tinting film, which would offer a wider selection of color tints, as well as metalic/reflective films.