On Mon, 3 Aug 2015 11:00:36 -0400, Frank Krygowski
wrote:

On 8/3/2015 7:58 AM, John B. Slocomb wrote:
On Sun, 2 Aug 2015 11:43:05 -0400, Frank Krygowski
wrote:

FWIW, I find eyeglass-mounted mirrors to be much superior to helmet
mounted ones. Positional stability is better, ease of attachment is
greater, and of course it works with any (or no) hat. And as a little
detail, I can even use it flat-water kayaking, to make sure my wife
doesn't get too far behind in her boat.

And isn't it interesting that helmets are still number one the minds of
Americans in the "bike safety" category? Have you ever been
complimented for obeying the rules of the road? For bicycling only when
sober? For properly choosing your lane position? Probably not.

But a funny hat intended to prevent the 0.6% of the brain injury
fatalities in America that occur while cycling? Oh, gosh, that's very
important.

Out of curiosity do you wear glasses? I ask as I tried a helmet
mounted mirror to see whether I wanted to use one and it almost drove
me crazy. I wear bifocals and the mirror was "above level", if that is
the right description, and when I looked at it, it was through the
upper, "long range" part of my glasses. Couldn't see anything but a
blur. tipping my head back to use the lower part of my glasses didn't
work either as, of course, when I tipped my head back the mirror went
up too :-)

Yes, I do wear glasses, which is one of the reasons I like
glasses-mounted mirrors. Instead of standard bifocals, mine are
"blended" bifocals.

I don't understand your problem, though. I position my mirror so it's
visible through the top left corner of the glasses lens. That's in the
"distant focused" portion, so it works perfectly for viewing the image
of a car or other cyclist who's a long distance away. Remember, you're
not focusing on the mirror itself, but on the image in the distance.

If the mirror were visible only through the "close focus" portion of the
bifocals, there would be a problem; but that's not the case.

It must be my eyes than as I just tried out your theory with as hand
mirror and there is a distinct difference in how clearly I see the
reflected image in the mirror when I look through the top or bottom
portion of my glasses and that difference also varies depending on how
far the mirror is from my eye.

It is also apparent that different mirrors have a different focal
length or whatever as if I look the central "inside" mirror in the
truck I get a different prospective than when I look in the "wing"
mirrors with both mirrors are essentially the same distance from my
eye. In the wing mirrors the object appears to be much further away
than the inside mirror shows.

I have the suspicion that a glasses ort helmet mounted mirror is a bit
more complex than "just stick a mirror on there".
--
cheers,

John B.