Sunday, August 03, 2008

Pinhole Lenses: More than Meets the Eye; Less than I'd Hoped.

You may have seen ads for glasses with pinhole lenses. You probably think they rank right up there with the "x-ray specs" found in the back of old comic books. Nope. These suckers work.

I was approached by the webmaster of pinhole-glasses direct who flattered my ability to describe things. Well, flattery works to a point, but not to the point that I'll review a product blind. However, as a person who has nearly been blind and has always had some sort of optical prosthesis, I found the whole idea of pinhole lenses inherently interesting.

Anyway, I took a look at the sight (pun intended); was instantly beskepticled (ibid) and told them that I'd need a pair to check out and would not promise a positive review. One small thing gave me hope and pause.

Please Note: Pinhole glasses are meant to be used only for stationary viewing. It is dangerous to use them when you are moving as it affects peripheral vision of the eyes.

When there are warnings attached to something, it strongly implies that whatever it is, it succeeds in doing something.

Anyway, they came, I tried them and they work, kinda, sorta. Well enough that the concept is well worth exploring, not so well that I could use them to entirely replace my glasses. They do work better the longer you wear them, and for people with mild prescriptions, I think they are well worth trying out. If nothing else, they are an lusciously cool accessory; kind of Fellini Goes Punk and they are obscenely comfortable.

For hand crafters, I'd suggest buying three or more and hand-painting them.

The first thing these people need to do is market what they have as a fashion accessory. Coat the lenses in various colors. Have a rainbow of frames. And then, get in contact with the technical people at to see about creating a product that's ideal for printing on. Here's a quick concept sketch.
There are any number of places where specialty-printed wraparounds would be popular. Sports events, for one. But consider how cool it would be to have shades that match your shoes and bag. Totally boutique! And right now, it's becoming possible to stock a boutique with art-printed originals. I think the existing material really lends itself to that application; it has a stiffness and conformability that should make it possible to create a single-piece printable product. It will probably require a simple frame, but that should be straightforward.

I wrote large parts of this review while wearing them. I'm extremely astigmatic and have artificial fixed focus lenses in my eyes after developing cataracts. Well, these do actually correct my astigmatism, and I can see the downside to moving your head - your vision blurs suddenly. I found that my brain compensated very quickly, both for the oddly spotty (literally) vision (referred to on the site as "the honeycomb effect") and the drastic reduction in the total amount of light. (Not a downside here in Nevada, I should add.)

I've never really had peripheral vision that I can recall until I did get my new lenses installed. I used to be so extremely near-sighted that the world was a blur without my coke bottles, and my brain is used to relying on peripheral vision for motion detection alone. Your mileage may vary on this point, but AS a point, it could be easily addressed by making a wraparound style.

I think it may also enhance the brain's ability to detect motion - I think it would be a great idea to get some data on this; if so, these might be of use in sport protection goggles.

I did try wearing them over my bifocals and found that suddenly my entire field of vision was available with full sharpness - indeed, sharper (if dimmer) than my corrected vision alone, and without the annoying search for a "sweet spot." It's very difficult to tell exactly, how well it would work with the pinhole layer actually integrated with a prescription lens - but my intuition and crude experimentation says that it's well worth finding out.

From the site:

Pinhole Glasses are special tools
In Pinhole glasses, holes of 1-1.5mm are spaced regularly using laser technology.

Yeah, that would probably be better. These pinholes are molded sheet plastic and I suspect that it's a stock sheet that is not really designed for the task. Nonetheless, it certainly does work. And the fact that the holes are actually conical in cross section may be a feature. It may not be. More data is required, and I've no way to go further along these lines.

Standard boilerplate continues, likely cribbed from some wiki. It's also clear that the English version of the site is written by someone who is quite sure they write fluent English.
Alas, no.

They may not be suitable for use in some instances.

Wearing pinholes affect your peripheral vision. They should not be used when you are driving or while moving about. It reduces the amount of light entering your eyes. Therefore, it cannot be used in environments having dim light. Wearing pinhole glasses does not prevent harmful UV rays from entering the eyes. So, do not use them to view the sun. It is also not useful for people measured as requiring lens of more than 6 diopters. Other eye problems like diffraction will prevent them from experiencing any significant benefits upon wearing pinholes.

It is always advisable for young people to avoid using any visual aid. Working on their eye muscles can improve their vision considerably.

As I said, the entire site comes across as a scam; this is not aided by their promotion of expensive "acupressure goggles."

As it happens, I'm not at all skeptical about acupressure; what I am skeptical about is the ability to automate an intuitive art, and extraordinary claims require extraordinary evidence.

To say that the links to supporting science for these products is sketchy is charitable. But leaving the accupressure goggles aside completely, there is a great deal of science, history and experience behind the use of pinhole lenses and the application of some real optical science to the matter would result in a better site and a far, far better product.

Guys; Go thou forth and find ye an optician and an optical physicist!

Meanwhile a set of these plus a workbook on the optical effect is well worth marketing to science classes - with various editions for college, middle schools and lower grades. It's possible to directly observe the physical principles at work far more clearly than by other means.

I'd suggest connecting with education writers and publishers. That could nicely fund further R&D - or indeed, produce the same results for free from fascinated bespectacled minds.

I wish I understood the physics better myself, but I have a few questions based on what little I do understand, and I hope someone will contribute answers.

Would smaller holes in a tighter array work? Because it they would work, they would work better. I did a quick experiment using a flyswatter that has square holes much more closely spaced. It worked, but not as well. However, it worked in such a way that it was easier to bring a line of text into focus.

Does the plastic have to be opaque? Because if the plastic were sun-glass lenses, that would definitely improve the experience.

Would a thin film with ideal sized holes (laser drilled, perhaps) work if applied to ordinary clear or tinted lenses? Could the film be printed instead of drilled?

And would it make sense to consider creating pinhole/slit arrays specifically for individuals?

The advantage would be that you might be able to literally PRINT lenses, or use any number of inexpensive Computer Aided Machining tools to produce something that would work well enough at a very, very low cost per unit - and this could make a huge difference in the third world. Heck, it would be pretty darn cool right here. But this needs to be stated strongly: What exists right now is good enough to make a huge difference in the third world.

Finally, if you took a hologram of an ideal constructed pinhole matrix and lens combination and put it in a frame - would that work? I seem to recall something to the effect that hologram lenses were used in satellite cameras, to save weight, and I've always wanted my glasses to be as light as physically possible.

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