Thank you everybody for your helpful suggestions.

I shall certainly try a spot of bright paint on the sights and see if that helps.

Also I remembered that when I go to have my eyes checked they fit a pinhole in front of the eye and suddenly I can read all the letters on the chart!

So some room for experimentation.

I may get a Crosman 2240 to play with and try the red dot idea.

Its either that or stick to my rifle..

Regards

Andrew