What is the England Hockey policy on protective glasses?

Please refer to The Rules of Hockey 4.2  "Field players: are permitted to wear throughout a match for medical reasons only a smooth preferably transparent or single coloured face mask which closely fits the face, soft protective head-covering or eye protection in the form of plastic goggles (ie goggles with a soft- covered frame and plastic lenses); the medical reasons must be assessed by an appropriate authority and the player concerned must understand the possible implications of playing with the medical condition"