I learned the dish soap method when I ... accidentally dropped them in dish water.
It is AWESOME.
It is amazing for sunglasses. Clarity is critical for driving, but they also seem to build up oil faster than normal glasses. Dawn makes them meticulously clean.
If you leave your sunglasses in the open in the car, it might be collecting the offgassing from the plastic - that same haze that accumulates on the inside of your windshield. I keep mine in a closed container and it seems to do just fine.
It is AWESOME.
It is amazing for sunglasses. Clarity is critical for driving, but they also seem to build up oil faster than normal glasses. Dawn makes them meticulously clean.