another important property of a photon is its polarity. if you saw a giant photon coming straight at you, it could appear as a swath whipping vertically, horizontally, or somewhere in between. polarized sunglasses stop photons swinging up and down from passing. this is how they reduce glare as light bouncing off of surfaces tend to fly that way. liquid crystal displays also use polarity to control which light passes through. some animals can see light polarization.