Ptosis Surgery - Plastic Surgeon Vs. Ophthalmologist Surgeon?

Hello, I have so called 'bedroom eyes' and under-eye puffiness. In the past two years due to either contact lens usage or age (I'm 45) or hereditary factors, I've noticed that my eyelids have dropped quite significantly. I use eye drops to lift them and that's worked for a while. My ophthalmologist recommended ptosis surgery which is covered under medical insurance in Canada. My question is, is it better to have this surgery done by him or a plastic surgeon and have both upper and lower eyelids done?