Silver polish is actually finer than brasso - at least where
spectacles are concerned.

If you have a stuffed anti-reflection (AR) coating, Etch All can
remove it with care. Silver polish Brasso polish Toothpaste re
spectacles.

However polishing out scratches of any depth may affect the
prescription re distant text reading. You can pick up new glasses with
1.67 lenses (ultra thin) of non-bifocal with "traditional gold frames"
for £47.50 delivered from onestopglasses and similar places (eg, Solo
10 at that website are £12.50 for the frames, -4.50 lenses will push
you to ultrathin so £35 extra). Worth delegating an old pair for DIY
use.