Fishing is all about vision
Struggling to see your float as well as tie a hook?
Unless you have perfect vision and are under 40 you are likely to find a long days fishing quite challenging
Float fishing and quiver tip require long periods of concentrating on a tiny target against a reflective water backdrop combined with tiny hooks and fine line
Polaroid sunspecs are a start but only really work if you have normal distance vision
(less than 6% of the population have) the other 94% are either long or short sighted most with a pinch of astigmatism thrown in.
Add to that the over 40's will need some kind of help with close work, tying hooks etc and it's little surprise that a day's fishing can leave your eyes tired and strained
A bifocal or varifocal with full correction for distance (float) and near (size 16 hook) is a start
The can be made with polarizing lenses
Or you can consider the latest flush fitting polaroid clip-ons which attach to custom made frames with tiny magnets