Fresnel lens

Materials that produce light instantly are called fluorescent. The atoms inside them absorb energy and become “excited”. While returning to the normal state in approx. a hundred thousandth of a second (10-9 to 10-6 sec), they release the energy as tiny particles of light called photons.

The Fresnel Prism and Lens Co. has been providing 3M Press-On® Prisms and other quality products to Eye Care Professionals since 1987.

Fresnel Light

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Basically, there are 3 main forms of luminescence: fluorescence, phosphorescence and chemiluminescence. Two of these, namely fluorescence and phosphorescence, are forms of photoluminescence. The difference between photo- and chemiluminescence is that in photoluminescence the luminescence reaction is triggered by light whereas in chemiluminescence the light emission is triggered by a chemical reaction. The basis of both forms, fluorescence and phosphorescence, is the ability of a substance to absorb light and then emit this light at a longer wavelength which means lower energy, just the timescale in which that happens is different. While in fluorescent reactions the emission takes place immediately and is only visible as long as the light source is on (e.g. UV lights), in phosphorescent reactions the material can store the absorbed energy and release it later, resulting in an afterglow that persists after the light has been switched off. So, if it disappears immediately, it’s fluorescence. If it lingers, it’s phosphorescence. And if it needs chemical activation, it’s chemiluminescence.

Fresnel Blender

Some families were very artistic and creative, and they would decorate the patches for their kids but how many families have an artist in residence?

In phosphorescence this is different. Here you have fast (10-11 to 10-6 sec) intersystem crossings from singlet excited state (S1) to an energetically favorable triplet excited state (T1). This leads to inversion of the electron spin and these states are characterized by parallel spin of both electrons and are metastable. Here the relaxation occurs by phosphorescence, resulting in another flip of the electron spin and the emission of a photon. The return to the relaxed singlet ground state (S0) might occur after a longer delay (10-3 to >100 sec). In this process more energy is consumed by non-radiative processes during phosphorescent relaxation than in fluorescence, leading to a higher energy difference between the absorbed and emitted photon and therefore a bigger shift in wavelength.

Fresnel effect

Trusted, Innovative, Global. The Fresnel Prism and Lens Company is an international supplier of specialty eye care products utilized by medical professionals to diagnose and treat patients afflicted by strabismus, amblyopia, diplopia, and other vision disorders.

The company was founded as a distributor of the 3M Press-On prisms and lenses, thus the company name.  Todays’ product line has evolved to include complimentary products addressing the needs of vision practitioners and patients.  Eye patch product lines were developed to resolve deficiencies of existing products.

Fresnel Aputure

Fresnel pronunciation

MYI (MY Eye) Patches came about because the eye patches for treating “Lazy Eye” (Amblyopia) were dull and boring.  They had no personality, NO Pizazz!  They were not made in America!  And, the brand that was most popular on-line were made such that you could see through them!  Yikes!!

Calmbacher Str. 22 75323 Bad Wildbad Germany

Fresnel equations

The word luminous basically means giving off light. Most objects in our world give off light because they are in possession of energy that originated from the sun, the most luminous object we know and that we can see. In contrast to the moon who seems to give off light, but is only reflecting it from the sun like a giant mirror made of rock.

Fresnel company

In 2004, we developed a patch that uses a US made medical adhesive to stop the peeking.  We added a black occlusion layer to ensure the vision is occluded.  We put the Pizazz in the patch with more than 20 designs that can be mixed and matched providing a custom pack of patches every time!

Made in Minnesota with American made materials by an American small family business – it does not get much better than that!  Check our on-line reviews to see that it really does get better!

We all think of something glowing when we hear the words luminescence, fluorescence or phosphorescence but the mechanism that stand behind these effects are somehow different. So, the question is, what sets them apart from each other?

As an example, you could imagine a night club where the fabric and teeth glow under the black light (fluorescence), the emergency exit sign glows (phosphorescence) and also the glow sticks glow (chemiluminescence).

Calmbacher Str. 22 75323 Bad Wildbad Baden Württemberg

Technically speaking, fluorescence is a radiative mechanism by which excited electrons transition from the lowest excited state (S1) to the ground state (S0). During this process the electron losses a bit of its energy by vibrational relaxation, resulting in the emitted photon having lower energy and therefore longer wavelength.

Looking at phosphorescence we need to take a short detour into electron spin to understand the differences between fluorescence and phosphorescence. Spin is a fundamental property of an electron and a form of angular momentum that defines behavior in an electromagnetic field. The spin can only have a value of ½ and an orientation of either up or down. An electron’s spin is therefore designated as +½ or -½, or alternatively as ↑ or↓. If electrons are on the same orbital of an atom, they always have an antiparallel spin at single ground state (S0). When promoted into an exited state, the electron maintains its spin orientation and a singlet excited state (S1) is formed, where the both spin orientations remain paired as antiparallel. All relaxation events in fluorescence are spin neutral and the spin orientation of the electron is maintained at all times.

Allowing the child to have a choice in the design they want to wear increases compliance.  Allowing the child to choose their favorite designs eliminates wasted eye patches that they will not wear.