Merrit Disk Eyepieces


January 2, 2003, 08:39 PM
I just learned that the little plastic thingy I occasionally see attached to some competitive shooters' glasses at the range is called a "Merrit Disk" (sp?).

Could someone fill me in on the history and workings of this device? Only for 'old timers'? What gives?

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Standing Wolf
January 2, 2003, 09:23 PM
I've been using one several years. The adjustable narrow aperture helps focus my aging eye. I use it with both iron sights and the red dot scopes on some of my .22 caliber pistols. It makes an enormous difference!

Aim your browser at and squeeze the trigger slowly and gently.

January 2, 2003, 09:29 PM
There is a brief write-up on the Merit Optical Attachment in the Jan/Feb 2003 issue of American Handgunner page 67.

In short, the device is a pinhole "collimator". It blocks out all parts of the sight picture except for the central "ray". Since the central ray is always in focus, the sights are now in sharp focus.

This helps for us old farts with presbyopia that require reading glasses to focus on anything within arms length.

January 2, 2003, 09:38 PM
Don't ask why, but they remind of these darts without the shaft. I'd feel silly wearing them but I haven't tried one out yet so I won't speak until then.

January 2, 2003, 09:41 PM
A small aperture increases the focal depth of field (helps with the task of keeping both sights and the target in focus) and can eliminate minor astigmatisms (partially compensates for some vision problems).

Anyone can use them.

January 2, 2003, 10:33 PM
Been using one for nearly four years. Every "old fogie" on the range comes up to me and asks about it. I give them my glasses (+25 diopters) along with the Merit Disc. Within 20 seconds they want to know where to buy one.

They work.

January 2, 2003, 10:45 PM

Thanks for the information.

I understand the principle - I've sharpened a long range view before by pushing my fingers and thumbs togethers to create a makeshift aperature... not while shooting, though.

Looks like they are trying to reach out to more than the old fogies with the slogan 'Providing clear sight pictures to shooters of all ages.'

Is this considered 'cheating' in bullseye leagues?

January 2, 2003, 11:51 PM
"Is this considered 'cheating' in bullseye leagues?"

A few years back it was not allowed. From my understanding, various leagues now allow them. (I'm too far gone these days to compete).

A word of advice on the use. As I'm sure you're aware, your head placement has a lot to do with shot placement. The disc must be in the same place every time, or you'll shoot to a different POI every time you re-adjust. In one respect that makes getting head placement more predictable, but it also requires some work to get the disc placement repeatable.

Tom A
January 3, 2003, 01:02 AM
I've tried pinhole glasses, similar to these: (

with positive results. Same principle as the Merit single aperture, only with this setup you have an array of apertures to choose from while sighting. I can't say that I use these glasses regularly, as I can move the rear aperture on my target rifle back and close enough to my eye so that the extra pinhole lens is unnecessary.

What is cool is using them to sight a milsurp rifle and being able to see the rear leaf, the front blade, and the 100-yard bull all crisp and clear at the same time!

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