The primary job of an eyeglass lens is to correct defective vision – nearsightedness or farsightedness, for example. It can also remedy other visual impairments such as astigmatism or a condition that the experts call presbyopia, or the increasing difficulty to focus at close range as we get older. The minimum requirement to be met by the lens is that the eye can see clearly again when looking "straight-ahead." This does not necessarily mean that we can see as well as people with perfect vision. And this is a challenge that we have been addressing at ZEISS for more than 100 years. Our goal is to provide eyeglass wearers with clear, natural vision in all directions, not just straight-ahead.

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Our eyes move behind our lenses. And the movement of our eyes varies from one person to another, and every frame sits differently on everyone's face. That is why the customization of modern eyeglass lenses is extremely important.

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A modern lens takes all of this into account thanks to individualized designs. A prescription lens has a different optical power toward the top or side of the lens than when we are looking straight-ahead. The design must therefore be optimized in such a way that the best possible correction is achieved at the top and the periphery of the lens. This must all be adapted to the wearer's prescription and to the fit and shape of the frame.