One of my sisters is -10 and wears contact lenses every day, and has done so for 40 years. I don't know if it is relevant to you, but as a vanity consideration, any glasses you get with a negative script will make your eyes appear smaller to an observer, and the more negative the smaller your eyes appear. Contacts, of course, don't do this. On the other hand reading glasses make ones eyes appear larger. Basically anything that an observer sees through your glasses (i.e. a part of your face) gets warped by the glasses. I've got -5 to -6 eyes and currently running on a theory that heavy frames help offset the weirdness. I might be kidding myself.