|Vision is something we often take for granted
especially in outdoor situations. ANY SKILL (even well practiced skills)
becomes very difficult without our eyes to help us along. I have often
wondered how Native American and other primitive civilizations faired when
faced with vision problems. Surely they had near-sighted and farsighted
peoples right? Maybe they just delegated hand-skills such as basketry to
those with Myopia (nearsightedness) and relied on those with Hyperopia
(farsightedness) to hunt or scout. I find myself among the nearsighted group
yet would not resign myself to only practice hand-skills if I lost my
glasses in the woods and had to fend for myself.
The solution is an
application of physics, yet is not new at all. We see that vision correcting
or vision protecting devices have been used by many ancient peoples. An
example is the snow goggle used to reduce glare by the sun on the bright
snow. The slits were basically mimicking our eyelids as we squint.
Pinhole goggles so named for the small pinholes placed in a material to
reduce excess light rays and assist in our eyes imaging of objects are a
good solution to broken or lost glasses. Making them is a helpful skill to
understand before you find yourself making them without glasses! They are
essentially the same as primitive snow goggles but imitate the pupil’s
ability to retract when focusing versus the eyelid as we squint.
How Pinhole goggles work
Pinhole goggles provide an endless depth of focus when the eyes are not
correctly focusing by reducing the amount of excess scattered light rays to
the retina. They are good for helping with refractive errors of the eye. A
refractive error means that the shape of your eye does not bend light
correctly resulting in a blurred vision.
So lets get to work.
Pinhole glasses can either be single holed or multiple holed. Many holes
allow for more light and therefore easier to see but may limit the focusing.