For martial artists, the eyes has always played a major role. The method of seeing is shared in many different arts, some with different emphasis and rationale but always explainable.
There comes a stage though where to obtain perfect vision, we have to abandon the eyes we have. Musashi apparently wrote the need for a budoka to see what is there and what isn't there. I do not need to explain that the meaning is not literal here.
So what is perfect vision? Well to take it step by step, first we ask what is timing? Surely timing requires some understanding of causal relationship between uke and nage. Thus timing is all about reacting in the appropriate manner, at the appropriate speed, angle and force and at the appropriate moment. Now that is a lot of appropriate variables. Are our eyes up to it? Typically our eyes connect to the cerebral cortex before allowing for reaction by the brains logic. Studies have shown that this speed is slower than that of reaction that comes from the medula oblangata. Further studies have shown that well practiced martial artists have short circuited the reaction time by using trained reflexes triggered by the medula oblangata. And that's why we are suitably impressed at boxers who weaves around the explosive jabs, and baseball players that bats incoming 180mph balls with such skill. Using just the normal eye to cerebral cortex reaction time, these feats are impossible.
Still, bypassing the longer route is not yet Perfect vision. When perfect vision occurs, uke himself understands that nage no longer has an opening. He feels constraint to attack anywhere. Nage has complete control of uke by just seeing uke's center even without doing anything. And if uke attacks anyway, nage can move casually not at all requiring speed and reflexes to counter the attack.
To get to perfect vision, one can no longer use the eyes alone. But knowing exactly where uke's center is and starting with nage's positioning of perfect alignment to that line.