One of the enhanced vision techniques taught in certain US military classes is to not look directly at what you are trying to see, rather look slightly beside it, below it, or both. Focusing on a point slightly nearer or farther away than the object you want to see may also help. This has to be practiced as no two people will find the same 'aiming point' correct and it is not the natural vision process. It is not something you can do without practice! This also develops your peripheral vision acuity because in effect, this is the part or your vision you use to do this. Learning the technique is best done at night (in someplace safe, not while doing anything more dangerous than walking) where the 'target' is a known size, shape, and distance away but blends in with the background or surrounding objects. Scan slowly till you first see the 'target' and you'll notice that you're not looking directly at it, and that when you do it disappears again! This technique also works when looking into the sun, but is less effective in light than in the dark for some reason. It still enhances your vision though. Being that I learned this second-hand from a Special Forces friend long ago, I can't much better explain it other than to say that once you master the technique, you will be amazed at how much more you will see that was always there which you have simply been missing so far.
Eye health also matters. I take a bilberry and lutien supplement and get enough carotene in my diet. The effect here is more slow-acting and is more important for your night vision- special bilberry jam rations were issued to pilots of night bombers in WW2 as this was the best source they had back then. I began this routine when I was 45 and I was having trouble seeing the road markings at night in the rain. Two months later I could see them as well as I could at 25- quite a difference- and at 55 now it's almost that good. Give this a couple months to work but you'll notice an improvement begin in 2-3 weeks.
I'm neither a 'whacko' or a pilot, I just know that all this really works and I hope it can help others gain some extra safety as it has done for me.