Directives Regarding Players Wearing Spectacles and Jewellery
Law 4 is quite clear:
 
“A player must not use equipment or wear anything that is dangerous….
Non-dangerous protective equipment, for example headgear, facemasks and knee and arm protectors made of soft, 
lightweight padded material is permitted as are goalkeepers’ caps and sports spectacles.”
 
Players must have something that will be secured tight to the head so that the spectacles or goggles won't fall off.
Other alternatives are contact lenses or sports goggles.
 
It is the decision of the match official (referee), in accordance with Law 4, to determine what is approved to be worn by a player.
 
Several years ago, FIFA endorsed a view of its IFAB Committee and stated the following: 
 
“New technology has made sports spectacles much safer, both for the player … and other players. We expect referees to take full account of this fact and it would be considered extremely unusual for a referee to prevent a player taking part in a match because he or she was wearing modern sports spectacles.”
 
We instruct our referees in accordance with these FIFA guidelines. 
If a player is wearing spectacles and states that they are in fact appropriate sporting spectacles, they must be allowed to play.
 
Law 4 is also clear with regard to the wearing of Jewellery.
 
"All items of Jewellery (necklaces, ring, bracelets, earrings, leather bands, rubber bands, etc.) are forbidden and must be removed. Using tape to cover jewellery is not permitted."