Pinhole Glasses: Do They Work?


The short answer is “yes”.  Now, your next question might be, “what the heck are pinhole glasses?”

Pinhole glasses are glasses that have one or more holes to see through instead of prescription lenses.  To make a quick sample, take a small piece of paper (about the size of a Post-It note) and use the end of a paper clip to poke a small hole in the center of the paper.  Hold that hole right in front of your eye so you can see through it like you’re trying to peep through a key hole.

The really cool thing about looking through a pinhole is that no matter what your eyeglass prescription is, it will help you see better.  Try it! Take off your glasses and look through that tiny hole you poked into that Post-It note.  Can you see better?  I bet you can.

The concept works by the theory that light rays (bouncing off objects your looking at) that come from straight in front of you will always focus properly on your retina.  Normally, light enters the eyes from all directions so if you are nearsighted, farsighted or have astigmatism the light is scattered on your retina and things look blurry.  Pinholes (with or without glasses) blocks all of the peripheral light so only the central light rays are seen by the retina.  It’s probably easier to imagine by watching this video:

As an optometrist, I use a variation of this every day to very quickly see if a patient with blurry vision simply needs an updated prescription or if some eye disease is causing the problem.  Remember, the pinhole temporarily fixes refractive power problems (such a nearsightedness or astigmatism). So if I have my patient look through the pinholes and their vision improves I know they need a new prescription.  If their vision does not improve I would expect a condition like cataracts or macular degeneration to be the cause.  Furthermore I would probably tell the patient to NOT buy new glasses because they won’t improve their vision.

Squinting is a variation of looking though a pinhole.  When you squint you squish your eyelids together so they are almost closed so you are seeing though a small aperture.

Think of your pupils as an aperture like on a camera.  If you turn up the light in a room your pupils get smaller right? Well, that smaller aperture helps you see better (especially if you need reading glasses but you can’t find them).  Conversely, what happens to your pupils when you are driving at night? They get larger to let in more light.  If you are not wearing an optimal prescription then your far vision will appear blurrier at night. That is a very common symptom I hear nearly daily, “doc, I’m having trouble seeing when I’m driving at night.”

One final thing.  There are “products” you can buy on the internet that claim if you wear their pinhole glasses it will fix your vision. Well, that is partially true.  As long as you wear their goofy looking glasses you will see more clearly (at the expense of losing peripheral vision).  But the instant you take them off your vision will return to the way it was.

Have fun and try looking through some pin holes… just not while driving!