Covering your plane with a visible/discernable theme is good and NOT flying in severe weather conditions is also good. But I found some years ago that to really ehance your visual perception the correct eyewear is impoortant. It goes without saying that if you require a visual correction, you should be wearing your eyeglasses. But whether or not you need corrective lenses I would suggest a pair of lenses with a soft yellow tint for those overcast days especially. I wouldn't fly without my special , yellow tinted, "flying glasses". By the way, they also are great for knocking down the harsh glare of oncoming headlights when night driving. FWIW from an optician.