First, if there is an impaled object it should be stabilzed in place. Second, both eyes should be covered so the person cannot see. The goal is to minimize movement in the effected eye. However since both eyes move in concert (normally) you must cover both.
Then provide emotional support to your patient since they are now effectively blind for the remainder of the call. This means guiding through what movement (walking or on the litter ie. "We are lifting you over the curb now") is going to occur as well as being very descriptive as to what you are doing treatment wise.