Once upon a time I used to be a real martyr to headaches but things have changed and it is now an absolute rarity for me to get one.
The things that have changed, apart from me having grown older and fatter, have to do with smoking and eye protection. When I used to get my very worst headaches I was both smoking serious numbers of cigarettes and I was also wearing sunglasses.
I can understand the cigarettes connection - only a fool smokes those things. And they used to be identifiably responsible for the headaches I used to get indoors at work. Since I stopped using them I actually don't think I've ever had one unless I had a cold coming on.
But outdoors and fishing it was a somewhat different story. Yes the headaches continued at a reduced frequency after I stopped smoking but always in bright light conditions and always when looking toward the sun - and always when wearing sunglasses.
And so I stopped wearing sunglasses and I have stopped having headaches - just like that!
You have to ask why and I don't know exactly but here are a few thoughts for everybody to consider. I wear fairly heavy prescription spectacles and I think I can state without being at all unfair that I have never had two pairs of identical glasses that actually were identical to look through. One of the fastest ways I know of giving myself a serious headache is to change between two pairs of identical glasses, one having a Sunglass Prescription.
I spent years having prescription sunglasses made at ruinous costs to myself and every time I put them on I knew I had trouble coming. It was probably the lens conformations because I tried Plain Sunglasses, Reactolite UV Sensitives (maybe the best way there has ever been of being unable to see anything at all in the last half hour of the fishing evening). I was a sucker for anything new - Hell, I even bought Old Style Contact Lenses when you had to be a serious hard man to use them without painkillers.
And then there was the Polarised Sunglasses business. I know that wearing Polarising Glasses is the very best thing to do when fishing rivers and I know that there is no way you could ever fish in Florida or the Tropics for Bonefish and the like without them - you couldn't fish, it wouldn't happen. And I know that they are almost wholly useless for Stillwater Flyfishing and I also think that they can be actually dangerous to your eyesight.
There is a reason for the danger - the one type of light that Polarising Glasses fail to stop is direct straight sunlight going whack into the back of your eyeball. They're fine at stopping bounced light coming in from all the angles but direct light and reflected direct light they do not stop.
And worse they con your eyes into being a little wider open than normal because they cut down on the general intensity of the ambient light your eye experiences - in other words they lower your natural defences against direct sunlight and compound the problem.
OK so you aren't wearing sunglasses so how do you deal with oncoming direct sunlight? You do what you tell your children to do - "Don't Look Into The Sun"!! And yes, wear a big wide brimmed hat or a baseball cap and let your eyes do what they were designed for. You will find that you can see pretty good except into the direct sun and you shouldn't be looking that way anyway.
Since I actively stopped wearing sunglasses except when they can actively improve my ability to catch fish which is about 95% of the time and stopped smoking cigarettes, as I say no more headaches. And when I do have to wear Sunglasses in Florida and when River Fishing I have taken to wearing those nice cheap polaroids that you buy from Kmarts for about $9 that I can put on over the top of my normal glasses and I think that that has helped too - certainly in Florida. I may look a prat but it is the very cheapest way. And it works for me!
I do have to say that Fly Fishing is almost the only sport I know of where you are far better off wearing glasses than not - even if they are just clear safety glasses. When you wear nothing in front of your eye your chances of getting a hook into your eyeball are too much to bear thinking about!