Another vote for the DGX mask. I bought two more once I started to use this in case they ever decide to stop making them.
They have had thier ultra-view on sale for a little while now. The mask itself is the same as the standard with a lens coating. I'm not sure if it really does anything, but good price.
DGX Ultra View Contrast Enhancing Mask
They have had thier ultra-view on sale for a little while now. The mask itself is the same as the standard with a lens coating. I'm not sure if it really does anything, but good price.
DGX Ultra View Contrast Enhancing Mask