Hold up your clean spectacles at an angle to the light. The light reflection then causes the subtle ZEISS laser mark to appear at the outer rim of the lens. The laser is operated with a wavelength that only permits a low level of penetration. After all, people looking at the wearer should be able to see the ZEISS quality seal, but the wearer's vision should not be impaired by it at all.
Our eyes are our most important sense organ. And since each eye is as unique as a fingerprint, it requires a customised visual analysis at your optometrist.
10 tips for greater wearer comfort
Is there a perfect pair of varifocal glasses for every occasion: for your job? For your favourite hobby or sport?
What's important for tailor-made glasses? Knowing how a patient's eyes interact.
Here's what your glasses can do for you when hunting.