Hi Steve,
Unfortunately, with age often comes failing eyesight and the consequent need to find aids which allow us to continue shooting rather just collecting old air guns.
I have managed to compensate for my less than perfect vision by fitting period aperture sights and obtaining a pair of prescribed shooting glasses which works fine for the moment anyway.
A nice addition to your Mk2 Airsporter would be a foresight protector like the one pictured below if you can find one.
Regards
Brian