Prescription Dive Mask Questions

I have not dove in a few years due to bad sinus. Used to dive with
contacts, now wear glasses. I am going to order a prescription mask for
snokeling.

I am blind with out my glasses for distance But do I have to have
bifocal lenses if my vision is not that bad closeup?

Should I buy a new mask or have lense put into the mask I have and
love? Wondering if the silicon would have degraded from being stored in
a hot attic for the last 2 years