For the professor, give them a little reminder of who you are, such as "Hi Professor <name>, my name is blah blah, I took your chemistry 100 class in Spring 2009." Include details that might jog their memory, if any. Then tell them your plans. Ask if they can write you a strong recommendation, since there is no point getting a LOR if it isn't good! Also, if possible try to give your professor a folder with your resume/CV, personal statement, and maybe an unofficial copy of your grades/OAT. If you don't live near them anymore, either email the files to them, or offer to mail it to them. Profusely thank them for their time and consideration, etc. etc.
For the optometrist, just ask them. I'm assuming they know you plan to apply to optometry school, so they probably expect you to ask them. Again, give them a folder with the aforementioned materials.
Also, if any of your LOR writers opt for snail mail method, give them a stamped and addressed envelope.
Good luck! Most professors aren't as scary as you think. 🙂