Helmut Wabnig wrote:
> On 16 Nov 2005 11:59:51 -0800, (E-Mail Removed) wrote:
>
>
>>Pinhole glasses to improve vision is simply a scam- they do not work.
>
>
> This statement is not true, at least not completely.
> What would "work" mean in such a context.
> You probably wanted to say,
> pinholes are not adequate replacements for optical glasses.
>
> Of course they work, pinholes are physically functioning optical
> elements, and can replace a camera lens
> Enter "pinhole" in Ebay:
> http://cgi.ebay.at/1-Laser-Pinhole-2...QQcmdZViewItem
>
>
> And when you combine many pinholes you get that:
> http://cgi.ebay.at/Pinhole-Glasses-R...QQcmdZViewItem
>
>
> The effect is surprising,
> it is worth trying from a physics standpoint,
> and may be useful for certain eye illnesses
> although I prefer normal glasses :-)
>
Pinhole apertures are commonly used in target pistol shooting to improve
the depth of field by simultaneously reducing the blur of the front and
rear sights as well as the target. There is no conventional transparent
lens which can accomplish that. For certain types of eye defects a
pinhole lens can provide better visual resolution than a full aperture
glass lens. The downside of pinhole lenses is Limited field and reduced
image brightness.
"glasses" with multiple pinholes were used in some parts of the world
long before glass lenses came into use. If the angular spacing of the
holes is approximately equal to the angular field of view of one
pinhole and in a hexagonal pattern. They give greatly improved
resolution, particularly for us old folks who have limited focus
accommodation. The "flys eye" effect takes some getting used to.