Nice Omega auto, I'd say from the mid to late 60's. If you can have someone pop off the case back, there will be a serial number on the movement - that number can be used to look up the approximate production date. Inside the caseback will be the reference number of the watch, which will tell you the model. I don't know enough about these to be more specific, but others may chime in.
Looks to be in very good shape, and once serviced, should give you years more of wear. Great to have a watch with a family connection to wear and enjoy! 馃榾