1) Nowadays, it's the custom that people who need glasses in order to see properly, can wear them in the public domain on Shabbat.

1) Some authorities permit wearing a plastic rain hat over a regular hat, if it won't fall off, but only provided one doesn't normally remove it if the rain stops. 2) If it can't be considered part of one's garments, and its not jewelry, then carrying it in the public domain is prohibited. 3) The authorities permit wearing rubber over-shoes for the same reason (even those who don't allow the use of plastic hat covers).

אסור לאשה לתת בגד על צעיפה וכן האיש על הכובע שלו מפני הגשמים שאין זה דרך מלבוש ואם כוונתן שלא יצערו אותן הגשמים מותר

1) Since these people can't walk without the stick, it's considered equivalent to their shoes, and not an extra burden that they are carrying (Mishna Berurah 301:63). 2) This is true, even if the person's body trembles when he walks (MB 301:64). 3) To carry the stick in the public domain. 4) This is because a blind person only needs the cane for direction, but not for the actual walking itself (MB 301:68). There are those who say that it's only prohibited if the blind person knows his way around; however, if he needs his cane in order to prevent tripping on things, he is like a lame person and may use his cane. 5) An ''Eiruv'' is an enclosure consisting of a series of poles or the like, with wire or string pulled tight over the top of them. It turns the area enclosed by it (sometimes even a number of neighborhoods), into a private domain, thereby allowing carrying in it. See also Chapter 94. 6) Even if the stick is decorated, and one carries it as a status symbol, it's still forbidden to carry it where there is no ''eiruv''. Although it's considered equivalent to jewelry, one is only permitted to wear jewelry, but not carry it in one's hands. However, within an ''eiruv'', one may carry a stick as a status symbol or if there is even a slight need for it. Only if there is no need whatsoever, is it considered disrespectful to Shabbat. (MB 301:66).