When  the subject of clipping (mowing) pastures comes up on here it is often criticized as wasteful, not necessary etc etc...

I use clipping my pastures with my flail mower as my primary weed control as I am (mostly) organic. This summer, for some weather related reason, there was an unusually heavy crop of foxtail which is a major eye irritant as cattle reach down through the foxtail for the grasses and clover underneath.  

Clipping along with annual pinkeye shots and year around Mineral-lyx barrels seems to control pink eye very well. I had none this year.

Where possible, clipping pastures seems preferable to fighting pinkeye.

ETA: face fly control with rubs doused with permectrin is also a big part of pinkeye control.