The opaque black cup is a solid hard plastic cup that will not bend or concave. The black with holes drilled is where we drill holes around the perimeter of the cup in a few layers and a hole in the center, this allows a little vision. The drilling of the holes does not compromise the sturdiness of the cup it will still not concave. The transparent Amber cup is a hard plastic that is see through, it however is not UV protection. The screen cup is made with our UV proof screen and popular for horses who need their "good" eye side protected from UV exposure. Our eye saver system allows you to have a cup on both sides if you should choose to.