if you do Liam
remember they are there to protect your eyes and improve your view into the water.
Its my opinion that yellow/amber lenses are the best for all round fishing in this part of the world.
Pink (rose) is pretty good too but i prefer yellow
it makes everyday feel 10 degrees warmer and improves your vision under clouds, it also makes light coloured flylines stand out better on the water, so its win, win all round.
I'm sure other people will have a different view, but brown,blue and grey lenses whilst great for driving, the tropics and the height of summer are a disadvantage in standard Scottish weather conditions IMHO. I'd try a few as i find most "fishing" glasses a little bit on the big side, never quite understood why
Sandy