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Exit pupils and age

Started by light trap, 04/30/2002 04:55PM
Posted 04/30/2002 04:55PM Opening Post
I sure am glad to see Zaharja posting about the fallacy of the "If you're over 40 you won't be able to use exit pupils larger than 5mm" Myth. I've been preaching against the blanket acceptance of that myth for over 2 years on the YG bino-net, and yet have run across folks that believe that so adamantly that they won't even bother to measure their own eyes. I don't know where that all got started, but Zaharja is completely right in that humans vary a great deal, and pupil size is but one area. I've never understood how otherwise bright folks can accept that there are midgets and giants, skinny people and obese, and yet cling to the erroneous notion that at age 40 one's eyes have deteriorated to an exact even amount. The reality is that everybody is different and pupil size is no exception. I'll get to see the proof of this at the end of the month. Somehow I doubt my max pupil opening size will shrink a full 1.5mm in the next thirty days.

The other myth I'd like to see tossed completely out is that matching one's max. exit pupil to one's binos is somehow relevant or necessary. Again, the reality is that around the perimeters of our pupils, our eyes aren't optimized for resolution and on the outer edges of the pupils are some naturally occurring aberations. Thus if one's eyes are capable of opening to 6.5mm, there really may not be any great advantage in trying to take advantage of the whole of the opening.

That plus the increased contrast of slightly higher mag. binos with slightly smaller exit pupils may be where the whole mythos of the "over 40 needs 5mm exit pupil" got started. To me, the contrast issue is the overwhelming value to be considered. To others, it's a matter of what can be held steady without noticeable shake. But the reality experienced by most everyone is that bino choice is highly subjective, and no magic formula will give one the right answer to blindly follow to get the right binos.

Mike Swaim