I have headaches behind mymy right eye. most painful when trying to sleep & close my eyes. could this be related to new glasses prescription?

Most unlikely.: Most headache pain is usually relieved by closing the eyelids, so pain increased by closing the eyes makes this immediately atypical. There is almost no possibility that your pain is triggered by your new glasses--unless you mean new contact lenses. I would be concerned about migraines, glaucoma, corneal injury--even brain or eye tumors. To answer your valid concern, request a proper medical exam.

Maybe: If your glasses are off, it could cause eye strain, headache, and other symptoms. It is usually not worse with sleep or eye closure though. I would get your glasses prescription rechecked and if your symptoms persist, you should see your eye doctor.