605. Jewelry
84:2 Certain types jewelry were forbidden by the Sages to be worn in a public domain on Shabbos, some for men and some for women. The reason for such prohibitions is the concern that the jewelry might be taken off to show to others. Nowadays, the practice has spread to be lenient in this matter and the authorities have written several explanations as to why this is. Nevertheless, a G-d-fearing individual should be stringent on himself. In particular, a man should be careful not to go out with a ring that doesn't have an open seal. (Mishnah Brurah 303:65 discourages a man from wearing any kind of ring outside an eiruv.) One should certainly not wear any kind of watch, even one connected to a gold chain around his neck, which is jewelry. A pocket watch is considered carrying and is overtly prohibited. (Regarding wearing a wristwatch in the public domain, there are authorities who permit it, though most appear to advise acting stringently in the matter - see Igros Moshe OC 1:111.)
84:3 A silver key, even though it’s a functional item, is also considered a piece of jewelry, and the practice is to permit it to be worn out on Shabbos. Eyeglasses, even if plated with silver, may not be worn out on Shabbos. (Our modern glasses fit our faces snugly and we tend to wear them continuously, making it unlikely that someone who wears glasses will come to carry them in the public domain. Based on this and other factors, there are contemporary authorities who permit one to wear glasses in the public domain. This position is not universal, therefore one should consult with his or her own rabbi for guidance in the matter.)