The pinhole glasses … What is it? What's the point? ?
We'll explain everything.
At first glance, one might think that it is an object to disguise itself during themed evenings…
In reality there is a whole other interest in wearing these strange hole glasses…
What does pinhole mean?
It is the contraction of two Greek words:
- Stenosis: narrowing of a conduit or natural organ
- Opsis: eye, view
We're talking about a pinhole.
This term is used by the vision professionals to designate a tool drilled with a hole of about 1 to 2mm in diameter that allows to perform visual acuity tests.
The hole is placed in front of the eye, which has a lack of acuity, which allows the rays of light to be concentrated in the center of the cornea. It is at this point that the refractive (the flexing of the optical wave) is the least pronounced.
If, by looking through the hole, the patient's Visual acuity does not improve or decreases, then it could be amblyopia or other ocular pathology.
On the other hand, if there is improvement, then it is a refractive problem, namely: nearsightedness or hyperopia.
A little Anatomy of the eye to understand the principle:
Let us distinguish in a simplified way, the 4 parts that we are interested in this article:
The IRIS: this is the colored part of the eye. It is a ring of muscles whose contraction allows to change the diameter of the input of the light.
The pupil: this is the slit through which between the light
The lens: this is the transparent disc modifying the convergence of light rays. It is he who makes the adjustment of the focus during the vision of close particular. (The cornea, outside the eye, does the bulk of this work (75%) in a non-adjustable way.)
The retina: this is the layer containing the Visual cells. (The information is then transmitted to the brain as nerve impulses through the optic nerve).
Below, diagrams explaining the difference between myopic and astigmatist:
Scheme 1 and 2: Instead of converging on the retina, beams of light entering the myopic eye meet at a point in front of the retina and produce a wide blurred circle on the retina, with beams of light penetrating the hypermetropic eye converge to a point behind the retina.
Scheme 3: Through the stenoic hole: the beam of light rays that passes through the hole is narrower. Light converges again on the retina, which decreases blurred vision.
How are the glasses designed?
It's a classic mount reminiscent of a pair of sunglasses. In the places of the "glasses", it is opaque plastic pierced with a multitude of holes of about 1 to 2 mm in diameter.
The hole plays the role of a narrow pupil and decreases the retinal scattering spot. It decreases optical aberrations and increases depth of field. This increases the visual acuity of a short-sighted person.
The concept is not new and you have surely already seen this type of glasses but with a different shape. The image that we have in mind is that of the Eskimo who, at the time, were already making it in ivory or shells, but it was in order to protect themselves from the Sun.
To read with this type of glasses, it is recommended to have a good light source. This is due to the fact that the brightness is precisely blocked so that the eye concentrates on what it needs to see, without being disturbed by anything it might see in normal times.
While the benefits are felt from 10 minutes of wearing a day, note that on the other hand, there is no point in wearing them for more than two hours.
Warning: If this was not obvious in all minds, remember that wearing these glasses is forbidden for any moving activity. At the top of these: Driving vehicles.
Book the use of these glasses for reading or any quiet activity
Generally, before 40 years, they are not useful because the Visual acuity is still good.
It is beyond that they offer a real interest.
Have you ever lived or seen some people keep away from their eyes what they were reading?
Does that mean anything to you? For those of us who are over 40 years old, you have probably already experienced it with the unpleasant and disturbing sensation that indeed, the view is no longer the same as before…
We're talking about "accommodation." This term refers to the ability of the lens to be bulging in close-up vision to allow for a clear vision.
Note that the "ponctum proximum" refers to the closest point that the eye can clearly distinguish. It is located 10 cm from the eye in the young adult. With age, this distance increases… At the age of 40 years, Punctum proximum can change to 20 cm and can reach 80 cm at the age of 60 years.
The advancing age, the crystalline lens hardens and loses its elasticity. He then finds it difficult to change his form to do what is called "accommodation". This problem is solved by eye correction for those who wear glasses. For those who do not wear them but are subject to this problem, putting glasses with grids reduces the field of vision and allows the image necessary for the focus to be entered.
(Note that wearing pinhole glasses is not recommended for people with more than 6 myopia dioptries.)
The first few seconds with these glasses on the eyes eliminate the blur effect and you see it NET without having to stretch your arm or squint your eyes.
We're here… When you bend your eyes, you decrease the opening of your eye. The effect of the pinhole glasses is the same, more accentuated. There is less light coming in, the eye focuses on what you want to read and the image on the retina is less blurred.
Which to choose… ?
Several models for each budget…
I highly recommend this model which has proven its worth and is popular on several sites dealing with the subject. The quality is at the rendezvous.
If you have a smaller budget, this model that I have in my possession does however the job!
In both cases, the principle is the same. Only the design changes and it will be noted that the more expensive model displays materials and a finish of a superior quality.
If you are subject to blurred vision up close, the pinhole glasses will surprise you with the sharpness of the vision they will provide you for close reading.
They are to be carried by transfers of 10 to 20 minutes, during the reading.
They do not heal the sight, but cause your eyes to move well, such as a kind of eye yoga, an eye gymnastics. With a regular port, the improvements will be visible from the first few months.
However, wearing these glasses does not exempt you from a consultation with the ophthalmologist of course.
For even greater benefits, it is good to practice eye gymnastics.
For a few minutes, several times a week, make movements with your eyes to strengthen their muscles. This without wearing the glasses is a complement.
- Circular movements
- From bottom to top
- From left to right
- Look away, then close, again from afar… and so on…
- Diagonal movement
- Make zig zag (up/down/up/down) with your eyes starting from left to right and vice versa.
30 seconds for each movement, taking care to move your eyes gently.
You can do these exercises even if you do not have pinhole glasses at home, it will be in any case beneficial.
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