What is Anti-Reflection Coating For Eyeglasses? How Can It Help Your Eyes?

Have you ever noticed how annoying it is when you're trying to read your laptop screen or work on a tablet but glare from the sun makes it difficult? It happens because the reflection of light off shiny screens makes them nearly impossible to see. 

Lucky for you, anti-reflective coating for eyeglasses eliminates this problem - especially if you wear glasses. So, what is anti-reflection coating? Let's jump to this post to discover now!

5 Types of Anti-Reflection Coating

Index-matching

Lord Rayleigh's discovery about the anti-reflective coating in 1886 helped to revolutionize optometry. At that time, optical glasses were susceptible to tarnishing. 

The main reason is that they would react with their environment and develop a layer of corrosion on their surface over time due to chemical reactions.

Some people think that old pieces of glass are just junk. But, as it turns out, they can be more useful than some may imagine! 

Rayleigh found this to his surprise when he tested the tarnish on these antique panes and discovered what seemed like a hidden property. They transmit light much better than new ones do.

The tarnished gold has a lower index of refraction than glass, so less light is reflected off its surface. In reality, it's just enough to make up for the two interfaces' combined reflection and even come close on account of being airy.

Graded index- anti-reflective coatings, also known as GRINs, can be a great way to cut down on the unwanted reflections that come from your lenses. 

They do this by making sure you get less glare for all incidence angles and frequencies, making it easier when looking at things up close and farther away.

Single-layer Interference

Simple interference coatings reduce the amount of light reflected off a surface. This can be done using one thin layer with an index equal to or close enough to be coated. This will result in zero reflection when incident upon from certain angles.

However, there'll still be minor fluctuations sometimes due to this same broadband reduction around central regions that occurs naturally, which is mainly because materials have imperfections, even though they may appear flat overall.

The ideal material for a single-layer coating would have an index of refraction close to 1.23. But, there is no such thing as low enough when it comes down to perfection and quality. 

The closest materials with good physical properties are magnesium fluoride (with a value of around1 .38) or fluoropolymers which can go up as low as 30 Index. 

However, these also prove difficult during application due to their high cost compared with cheaper options like window panes made out of plastic bottles.

MgF2 is a cheap and durable coating that performs well on higher-index glasses. The material's reflective properties depend largely upon its wavelength, with 1% reflectance recorded for visible light between 400–500 nm (the range includes most colors). This means it's best used as an anti-reflection treatment close to 500 nm where there isn't much else mixed into your vision.

Researchers have created an innovative new type of lens coating that functions as both an anti-reflection and refractive index changer. This could be the perfect solution for future eye care needs.

Multi-layer Interference

Silica and gallium arsenide, a higher index material, are used in tandem to create an efficient electric or optical coating. 

These complex coatings can also be made cheaper by using less expensive materials but with similar properties as their more costly counterparts. 

These advancements make them perfect for commercial applications where cost efficiency is key.

Absorbing

The so-called "absorbing ARC" is a type of anti-reflection coating that can be used when you want to keep transmission levels high but reduce reflectivity. 

They have many different uses in technology, from windows with better insulation to tinted glass that provides contrast. 

One of the most common types is absorbent AR coatings. These can use unusual optical properties exhibited by compound thin films produced through sputter deposition such as niobium oxide and titanium nitride.

These can be useful when you need to enhance your vision or want something new-looking instead of regular old panes.

Moth Eye

Moths have a special ability that allows them to see in the dark. They've evolved an anti-reflection coating on their eyes, which helps moths avoid being seen by predators during nighttime flights.

The hexagonal pattern of bumps on this surface works as an anti-reflective coating because they are smaller than the wavelength for visible light. 

Hence, it sees only one continuous refractive index gradient. It removes any interfaces between air and other media that would otherwise cause reflection back into our eyesight. 

Canon's SubWavelength structure Coating uses a moth-eye technique to reduce lens flare. This is biomimicry at its best, and humans have done it.

The moth-eye structures are a great way to split water and produce hydrogen. They're grown from tungsten oxide mixed with iron oxide to create an efficient photoelectrode for splitting the element itself.

Anti-Reflection Coating Applications

Anti-reflective coatings are a must for optical surfaces facing any light. They can help increase clarity, reduce glare and reflection on corrective lenses or camera lens elements, and protect solar cells from being scratched by harmful rays.

Corrective Lenses

Some people like to wear anti-reflection lenses because it enhances their cosmetic appearance. 

Anti-reflective coatings are often used in the design process, leading some individuals who have the normal vision to think that these products will provide a clearer vision than what is available without them.

However, aesthetic benefits only last for about three hours before fading away. So, if you're looking for longer-term effects, this type of lens isn't going to cut it.

Anti-reflective ophthalmic lenses do not decrease the visibility of the sun reflected off surfaces such as sand, water, and roads. These are called "anti-reflection," but they work by reflecting light that reaches them directly - not where it came from.

Anti-reflection coatings are designed to keep your lenses cleaner and easier for you with less work. These additional features can also make them healthier.

Photolithography

Imagine a world with no anti-reflective coatings. The photoresist would constantly be distorted by reflections off the surface, leading to image inaccuracies and distortion in your product.

These ARC's are used for many purposes, including helping reduce standing waves or thin-film interference during manufacturing processes using photography as guidance. This helps give us clearer pictures without error messages telling us what isn't working properly.

Conclusion

Generally, the applications for anti-reflection coatings are varied and include eyewear, camera lenses, military equipment, architectural glass, etc. 

If you're looking to add a layer of protection from reflections in your glasses or other optical devices, it may be worth considering adding an AR coating that will protect the surface of the lens. 

We hope that our article provides all the information you need to answer "what is anti-reflection coating?" Contact us today for more information on how we can help you find the right type of anti-reflection coating for eyeglasses and other products!