I think it is illegal, just like wearing a patch over one eye unnecessarily or using a steering wheel spinner/knob. Its ok for disabled people to use them out of necessity, but not voluntarily.
I don't think there is a specific ruling but could come under due care and attention type rules - subjective stuff.
In a time of universal deceit - telling the truth is a revolutionary act. George Orwell
When the debate is lost, slander becomes the tool of the loser. Socrates