Ted Bennett wrote:
> >Check it out.
> >
> >
http://sheldonbrown.com/eagle.html
>
>
> Sheldon't choice of lens for his glasses worn in the picture intrigues
> me. The lens is an unusual type known as a "Double D" which features a second bifocal above the
> usual line of sight. It is useful in situations where the wearer needs to have clear near
> vision in the upwards direction.
>
> It is most common among mechanics of the auto and truck persuasion, and may be used by Sheldon for
> similar reasons. But they would be useless for riding in anything but an upright riding position.
Actually, no. These are normal bifocals with the line higher than usual. The lower prescription is
right for a computer screen, the upper part is just my astigmatism correction.
These are the first glasses I've had since I needed bifocals that work for pretty much everything. I
have some more conventional bifocals, wiht slightly greater magnification, but neither the upper nor
lower part worked for me on a computer screen. I couldn't focus in the upper, and the lower was too
low so I had to crane my neck back at an uncomfortable angle.
It took a bit of persuading to get my optometrist to make these up, but they really work very
well for me.
Sheldon "Highliner" Brown +---------------------------------------------------------------------+
| A man of character finds a special attractiveness in difficulty, | since it is only by coming to
| grips with difficulty | that he can realize his potentialities. -- Charles DeGaulle |
+---------------------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com Hard-to-find parts
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