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I purchased a spectacle from an online website with anti-blue coating. The features of this product is mention here.

Once I receive it, I started using the product without testing the anti-blue coating, recently, I visited the optics store and out of curiosity I started to test the anti-blue feature of my specs, only then I realised that my specs is letting the (70-80% intensity) blue light to pass through without obstructing it.

When I called the online store they gave me explanation that I have high power hence it is not blocking it. My eye power is -5.25 and -5.75 without any cylindrical power.

I searched on the internet and couldn't find out any explanation to scientifically prove that their explanation is correct. Because as per my understanding it is a simple coating over the lens which doesn't allow to blue light to pass and so it should not affect my power.

Can anyone please help me understand how this is possible, I mean if the lens power matters or not?

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the optical power of the source is important. your glass with a specific coating can reflect a certain percent of the blue light. i.e. if blocks for example 95 percents of blue photons. and this work for your mobile phone or sunlight, but for a laser because of high optical power that the remaining 5 percents is still a lot and your eyes can see blue.

for example, if sunlight contains $10^3$ photon/s of blue color, after filtering (95% blocks) only 10 photon goes to your eye and the human eye is not sensitive enough to detect this.

but for a light source such as laser or high power LED or XE lamp the photon number is extremely high $10^{23}$ and after blocking 95 percent there are $10^{21}$ pass the coating and your eye can see it! (or maybe explode your eye)

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The blue is short wavelength and the coating might be designed for flat surface.

So the higher curvature will change a bit the angle of incidence and can make the coating less effective.

It is likely a design issue of the coating.

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