I was at 1000 yards on the weekend, and got blown away with mirage. I was lucky to get my first two sighter's in, 6 then a 5 which I promptly cut, as I could see the target clearly. Then I went for my first business shot, and looked down the scope to find that the lines had disappeared, and the black was a wobbly blob 
I have a Nightforce 12-42 x 56 BR, and while I backed down the power so I had a black blob, I could no longer see the white lines in the black. As for knowing where the Center was, that was a bit GREY too???
Does anyone have some suggestions on how we tackle this scenario?
Mirage can be a good thing, but this is the first time I've seen it that BAD!
Is there something like filters for the scope, or some other options for dealing with this maybe?
A polariser?

I have a Nightforce 12-42 x 56 BR, and while I backed down the power so I had a black blob, I could no longer see the white lines in the black. As for knowing where the Center was, that was a bit GREY too???
Does anyone have some suggestions on how we tackle this scenario?
Mirage can be a good thing, but this is the first time I've seen it that BAD!
Is there something like filters for the scope, or some other options for dealing with this maybe?
A polariser?