Well, pretty silly indeed.
Are you sure that it is random ? Said so : you've lost an eye, so, now, basically, you're a one-eyed troop, and if you put on a magic eye, well ...
I'm not sure that the game take account of your original number of eyes at the time of the calculation. It did at some point, because you can heal from this afflication, but, still, I have doubt ...
Whatever, be carefull with magic eyes ... I had once played SP with Abysia and all my fire combat mages were equiped with eyes of aiming. One time, my very best mage win a fight, and find a magical item : another eye of aiming ...
Guessed what : he put it at the place of his other (and lasting) eye ... and finished with big accuracy, but blind ...
Pretty useless on a battlefield, but still worth in a library : he ended game researching ... I wonder how he could read ?