Recovering from rhinoplasty is a healing process. Part of that process involves avoiding things you do day to day. This includes wearing your glasses. I like to ask my patients to hold off for 2 months. Even the lightest glasses can create a dent on your nose. Exceptions are patients who had nothing done to their bridge. They can go back to using their eyeglasses as soon the swelling calms down on their bridge. I also ask my patients to bring in their glasses so I can evaluate their weight. If you have any questions or concerns, bring them up with your surgeon so they can keep you on track for safe and happy result. Safety comes first.
If you have a nasal cast on it should be ok for you to wear your glasses. Timing is dependent on various factors that you should discuss with your surgeon that did your rhinoplasty as they may have specific instructions for you based on the techniques they used for your surgery. It is generally best to not put anything around your nose for 4-6 weeks at least, but this may vary based on the fractures that were done during surgery on your nose. Speak with your surgeon about his post-op instructions and specifically ask about when you can wear your glasses.