Jewelry, Eyewear and Watch Design Caliber Optics Balanced Eyewear by Hukaya Simon, Zachary Tipton Caliber Optics recycles metal to make eyeglasses. The .357 collection uses spent .357 magnum casings as a functional counterweight to render the glasses more stable for the user. The counterweights are swagged to the end of the temples to balance the weight of the frame front. The light semi-rimless frame front weighs around 6 grams and the counterweight weighs 6 grams per pair. The Beta titanium temples incorporate an electric discharge machined compressed spring. The flexibility of the temples associated to the balance of the frame makes the glasses more comfortable to wear.