When I started surfing last year I had to get back into contact lenses so I could see the set rolling in. A few weeks ago I tried something new. I drilled some holes in the plastic legs of my prescription sun glasses so I can tie them to a loop in my rashie. They are excellent, but even better is that they stop all that glare so I can stay out for hours in very bright conditions without the usual sun dammage to eyes. It is very good, and there is a bit of a coolness factor 
to help balance out my dorky surf hat 
Kadi look out for the fashion police mate,they will lock you up for wearing that sh1t
, but still on the run
Greg Brown was wearing boardies and sunnies at Torquay Point the other day. 'Cool' sunnies as opposed to say Oakley Sports Sunglasses... Pretty funny!
Tying to the loop is probably the best idea but you can get these fairly inexpensively from your local optom, floating cords ..i would probably incorporate both...be aware the salt and suncream will rapidly do a job on the lens material even if you rinse them after every surf .....pm me if you can't find one !
I considered the prescription sunnies option for a long time, I still think it's a good idea, but I'll stick with the contacts for now.
They're getting much easier to put in and I've found a good brand and supplier.
Because I only wear them on the weekend, a normal 3 month supply lasts me for ages.
Usually the lenses have a clear or hard coating on them which also will contain the tint if not polarized in most cases.This may start to peel or craze after prolonged exposure to salt either from your perspiration or the sea (more likely) ,combine with some suncream which tends to paste it onto the frame and lenses and the usual result is crazing of the lenses,doesn't always happen but pretty likely. The tint will fade after a period of time (years rather than months)as they are normally solutions ( vegetable based dyes) that bond to the outside lens coating (sharing a carbon molecule) in very simple terms ,but now days there are so many different lens materials/types etc just give a rinse and if they go off so be it ,just have another pair for the rockstar image back on land
I always found i could never surf nor kite surf in polarized lenses as instantly i lost depth perception because i could see down into the water (or should that be called surface level perception) and would misjudge the surface of the wave and bugger up turns . In Rx lenses they are too expensive to be dishing in the surf every day
Those free phone/id card lanyards are also useful as you can unpick them, stitch one end to the sunnies through the hole and then use a large safety pin on your rashie or to the zip lead on a wetsuit/ vest.
I wouldn't worry about the fashion police as
from a fashion view if those sunnies were a horse i would take them out the back shoot em and bury them next to my bucket hat .......
cheers
