Anchor Glasses StrapsAnti-Slip Glasses Ear Grip - 3 Pack - Stretch Fit for Sunglasses and Glasses Retainer Glasses Chain

Q: The legs on my glasses are 8mm wide at the end. Will these fit them?

The silicon grips are 8mm at each end on the chart size or the last photo of the grips. So, yes.

Q: Do these stop the glasses sitting on the bridge of your nose? I need my glasses to hover and NOT touch my nose due to an op.

No, they are designed to stop your glasses falling off if you look down, all glasses need three points of contact, ie ears / bridge of nose. you wont find ones that Hover, unless you use goggle type

Q: Would these stop me from looking over my glasses when I am playing pool

Absolutely they would yes. With these on, your glasses will not move a millimetre. So, if you're long-sighted and want to look over your glasses when playing pool then don't wear them, but if you want to have your glasses fixed in place when you are playing then do wear them.

Q: can these be worn when wearing a hearing aid behind the ear ???

I don't know. They are basically like an extension to the arm of the glasses. If the glasses don't interfere with the hearing aid, I don't think there will either. They sit quite low and can be adjusted lower if needed. They are also quite slim. Mine were thinner than the arm of my glasses.