QFT, just wear shades it is that simple lol.
That said, while it might be sexual harassment I don't think that "staring" should ever be punishable. If someone is following you then you can go with stalking but if they are just sitting and staring then ignore them or if it really bothers you leave the area. The world isn't a "safe place" so deal with the minor issues like this by growing some thick skin and ignoring the minor stuff >_>