Straight temple spectacles were machine produced from 1833 until WWI. Most lenses in this type of spectacle are oval. However, square and octagon lenses do come to the marketplace from time to time. Colored lenses used before 1875 tended to serve a medical purpose. The use of colored lenses as sunglasses date to around 1880. Straight temple spectacles went out of style in the late 1800’s but, continued to be made in small amounts until 1920.