Try "Extreme Glare Technology " coated prescription glasses from Zurich International in Cal.
Bruce Holden is the owner and an optometrist by trade. He knows our needs and is an awesome guy who stands behind his product.
He'll sell you frames or can use your old ones provided that they are in good shape. I sent my prescription from my Opthamologist( read M.D.) to him. Don't buy cheap stuff when it comes to your eyes.
One more thing, when looking at the sun, momentarily close one eye. Believe it or not, you'll see the plane better. Something I learned from an old timer while flying R/C.