LeisurePro S No, you don't need to specify left and right (the lenses are reversible for either side), but you will need to order one lens for each side; they are sold as a single lens, not as a pair. If you already have the mask, you can just order the lenses and install them yourself (very easy). If you are ordering the mask at the same time, we can put them in for you, just leave detailed instructions of what you would like in the 'special delivery instructions' box during the checkout procedure.

LeisurePro S These lenses are interchangable from left to right.