The material the lenses are made from
Lightweight eyeglass lenses made from plastic are the secret to incredibly thin and lightweight designs, even when high dioptric powers are required. The higher the quality of the source material, the thinner you can make the lenses. In the case of plastic lenses, for example, choosing the high-tech option over the standard material can reduce the weight by up to 50% (up to 40% in the case of glass lenses). That's quite a weight off your mind! And it applies to progressive lenses, too.
The method used to produce eyeglass lenses.
Another way of putting glasses on a diet is to use what is known as aspheric grinding: In the case of conventional ground lenses (spherical lenses), the front and back surfaces of the lens are curved like a sphere. In contrast, aspheric lenses feature specially optimized surfaces. In order to avoid a pronounced, aesthetically unappealing curvature of the front surface of the lens while simultaneously achieving perfect visual quality, the front surface of an aspheric eyeglass lens is optimized so that the surface flattens out from the center of the lens toward the edges. This makes it possible to make aspheric lenses thinner and significantly lighter while maintaining the same optical effect. Aspheric lens design techniques can be used to create flat, thin and extraordinarily lightweight eyeglass lenses – even for wearers with significant vision problems.
The right material for the frame
The frame and earpieces play an important role in determining the overall weight of the glasses. It's therefore important to choose a slim frame made from special, ultra-light material. For example, titanium weighs 50% less than conventional metal or plastic. That's why glasses with a titanium frame are the first choice for anyone who needs exceptionally stable yet lightweight glasses and the perfect solution for athletes and children. Offering the ultimate lightweight experience, today's ultra-thin titanium frames weigh less than 2g. But it's not just its low weight that has elevated titanium to the number one spot when it comes to materials for eyeglass frames and earpieces: titanium frames are extraordinarily light, robust and corrosion-resistant and can be produced in ultra-flexible designs as required. In fact this material is now so flexible that you can bend the earpieces without damaging them – they simply spring back into their original shape as soon as you let go. They also come in a wide range of outstanding designs, completely screwless and offered by many different brand manufacturers in a wide range of conventional and ultra-modern colors. The only thing these designs have in common is their extraordinarily low weight. Titanium frames are nickel-free, which makes them a great choice for allergy sufferers.
The design of the frame
The weight of a pair of glasses is also influenced by the size of the frame because this determines whether the glasses lenses will be lighter or heavier. The smaller the frame, the thinner and lighter the lenses.