[It helps that sunglasses, at least the modern version, aren't so much of a thing in Victorian England - their connotation to blindness obviously doesn't occur to Sebastian. One amazing-smelling slice of cake coming right up.]
Oh, there is. At present the only known method is being returned at "the world's" whim... [and surely there's another; it's just a matter of finding it] but obviously that is quite outside of anyone's control.