Just posing a question here, but wouldn't you want an NFO in alot of platforms to have eyes as good as the pilots? In fighters for instance in BFM, wouldn't it be good to have a WSO with equal vision to spot bogeys?
Even in my advanced age, I imagine that still I have maybe "20-10's" (rarely), or at least "20-15's" (certainly) but still no less than "20-20" eyesight (truly).
Nevertheless, my 'blind' RIO's often did indeed spot bogies, missiles, adversary A4's, or even some occasional birthday kid's Mylar helium balloons, long before I did.
One of the best weapons systems the Navy ever developed was the RIO.
And one of my more memorable experiences was the time we had multiple SAM launch warnings and indeed actual SAM's in the air, just prior to roll-in on a major, and very important target. I would have – and should have aborted the strike, given the multiple threat indications.
But my (junior but experienced, and sharp-eyed) RIO says, "I got 'em all, just roll in Cat … I'll call " break" if needed." Having been flying together long, I trusted him thoroughly… with our lives. He could fly us verbally as well as I could fly physically. Result, great hits and many secondaries on an oil refinery, and a few SAM's passing by, no threat.
Also, venturing into 'Po, it was always good to have a big tough RIO in tow, the bigger the better; but in hostile skies any 'sized' RIO's were better than nothing. Size didn't matter, but in war, the best NFO's were better than gold!
And anyone who would want to denigrate my better partners who flew with me in harm's way and did 50% of the work, (but thought they did 60%

) I should and would justifiably want to cold-cock the arrogant upstarts…even today at my advanced age. We (pilot/RIO) were a team that not only made a better difference, but also saved each other's lives, perhaps other's too, and we made that difference…together.