Buzz,

You are correct, Batha's statement does not hold water. See my comment above about misinformed experts. Consider this: Can a fighter pilot visually concentrate only for a half second on an inbound threat aircraft or missile? Or, is an outfielder able to only concentrate for a half second on a high pop fly? Or George Digweed able to only concentrate that half second when he's whacking crows at 60 to 70 yards? Or, can you only concentrate that same time on an 80mph oncoming car in your lane? Think about it, it is ridiculous. We know what the result would be in all these examples. As far as aging is concerned, effective accommodation is mostly lost to us by age 50, some sooner, some later...but that is totally irrelevant as accommodation only matters at a range of about one meter or less. Another gem I have read/heard from an "expert" is that your dominant eye is determined by which ever eye first sees the object. This is akin to stating that your dominant hand is whichever hand is closer to the hammer you want to pick up.